Frontiers of Physics

ISSN 2095-0462

ISSN 2095-0470(Online)

CN 11-5994/O4

邮发代号 80-965

2019 Impact Factor: 2.502



一年内发表文章 | 两年内 | 三年内 | 全部 | 最近1个月下载排行 | 最近1年下载排行

当前位置: 全部
Please wait a minute...
选择: 合并摘要 显示/隐藏图片
Numerical investigation of relationship between water contact angle and drag reduction ratio of superhydrophobic surfaces
Liang Yin,Hai-Feng Zhang,Shu-Yuan Shi,Yao Lu,Yang Wang,Xiao-Wei Liu
Frontiers of Physics    2016, 11 (3): 114701-.
摘要   PDF (419KB)

This paper proposes a novel bubble model to analyze drag reduction. The relationship between the slip length and air bubble height is discussed. The numerical relationship between the surface contact angle and slip length is obtained using the solid-liquid contact ratio in the Cassie equation. The surface drag reduction ratio increases by 40% at low velocities when the solid liquid contact ratio decreases from 90% to 10%. An experimental setup to study liquid/solid friction drag is reported. The drag reduction ratio for the superhydrophobic surface tested experimentally is 30%–35% at low velocities. These results are similar to the simulation results obtained at low velocities.

参考文献 | 相关文章 | 多维度评价
Recent advances in MXene: Preparation, properties, and applications
Lei Jin-Cheng(雷进程), Zhang Xu(张旭), Zhou Zhen(周震)
Frontiers of Physics    2015, 10 (3): 107303-null.
摘要   PDF (677KB)

Owing to the exceptional properties of graphene, intensive studies have been carried out on novel two-dimensional (2D) materials. In the past several years, an elegant exfoliation approach has been used to successfully create a new family of 2D transition metal carbides, nitrides, and carbonitrides, termed MXene, from layered MAX phases. More recently, some unique properties of MXene have been discovered leading to proposals of potential applications. In this review, we summarize the latest progress in development of MXene from both a theoretical and experimental view, with emphasis on the possible applications.

参考文献 | 相关文章 | 多维度评价
Laser-induced breakdown spectroscopy in Asia
Zhen-Zhen Wang (王珍珍),Yoshihiro Deguchi (出口祥啓),Zhen-Zhen Zhang (张臻臻),Zhe Wang (王哲),Xiao-Yan Zeng (曾晓雁),Jun-Jie Yan (严俊杰)
Frontiers of Physics    2016, 11 (6): 114213-.
摘要   PDF (5652KB)

Laser-induced breakdown spectroscopy (LIBS) is an analytical detection technique based on atomic emission spectroscopy to measure the elemental composition. LIBS has been extensively studied and developed due to the non-contact, fast response, high sensitivity, real-time and multi-elemental detection features. The development and applications of LIBS technique in Asia are summarized and discussed in this review paper. The researchers in Asia work on different aspects of the LIBS study in fundamentals, data processing and modeling, applications and instrumentations. According to the current research status, the challenges, opportunities and further development of LIBS technique in Asia are also evaluated to promote LIBS research and its applications.

参考文献 | 相关文章 | 多维度评价
A survey of dark matter and related topics in cosmology
Bing-Lin Young
Frontiers of Physics    2017, 12 (2): 121201-.
摘要   PDF (17860KB)

This article presents an extensive review of the status of the search of the dark matter. The first eight sections are devoted to topics in dark matter and its experimental searches, and the rest to selected topics in astrophysics and cosmology, which are intended to supply some of the needed background for students in particle physics. Sections 9 and 13 are introductory cosmology. The three astrophysical topics, Big Bang nucleosynthesis Section 10, Boltzmann transport equation and freeze out of massive particles Section 11, and CMB anisotropy Section 12 can all be studied in analytical approaches when reasonable approximations are made. Their original analytically forms, to which this article follows very closely, were given by particle physicists. Dark matter is an evolving subject requiring timely update to stay current. Hence a review of such a subject matter would undoubtedly have something wanting when it appears in print. It is hoped that this review can form a humble basis for those graduate students who would like to pursue the subject of dark matter. The reader can use the extensive table of contents to see in some details the materials covered in the article.

参考文献 | 相关文章 | 多维度评价
The rise of two-dimensional MoS2 for catalysis
Jun Mao (毛军), Yong Wang (王勇), Zhilong Zheng (郑智龙), Dehui Deng (邓德会)
Frontiers of Physics    2018, 13 (4): 138118-.
摘要   PDF (56346KB)

Two-dimensional (2D) MoS2 is used as a catalyst or support and has received increased research interest because of its superior structural and electronic properties compared with those of bulk structures. In this article, we illustrate the active sites of 2D MoS2 and various strategies for enhancing its intrinsic catalytic activity. The recent advances in the use of 2D MoS2-based materials for applications such as thermocatalysis, electrocatalysis, and photocatalysis are discussed. We also discuss the future opportunities and challenges for 2D MoS2-based materials, in both fundamental research and industrial applications.

参考文献 | 相关文章 | 多维度评价
In situ analysis of magnesium alloy using a standoff and double-pulse laser-induced breakdown spectroscopy system
Yong Xin (辛勇),Lan-Xiang Sun (孙兰香),Zhi-Jia Yang (杨志家),Peng Zeng (曾鹏),Zhi-Bo Cong (丛智博),Li-Feng Qi (齐立峰)
Frontiers of Physics    2016, 11 (5): 115207-.
摘要   PDF (4190KB)

To monitor the components of molten magnesium alloy during the smelting process in real time and online, we designed a standoff double-pulse laser-induced breakdown spectroscopy (LIBS) analysis system that can perform focusing, collecting and imaging of long-range samples. First, we tested the system on solid standard magnesium alloy samples in the laboratory to establish a basis for the online monitoring of the components of molten magnesium alloy in the future. The experimental results show that the diameters of the focus spots are approximately 1 mm at a range of 3 m, the ablation depth of the double-pulse mode is much deeper than that of the single-pulse mode, the optimum interpulse delay of the double pulse is inconsistent at different ranges, and the spectral intensity decays rapidly as the range increases. In addition, the enhancement effect of the double pulse at 1.89 m is greater than that at 2.97 m, the maximum enhancement is 7.1-fold for the Y(I)550.35-nm line at 1.89 m, and the calibration results at 1.89 m are better than those at 2.97 m. At 1.89 m, the determination coefficients (R2) of the calibration curves are approximately 99% for Y, Pr, and Zr; the relative standard deviations (RSDs) are less than 10% for Y, Pr, and Zr; the root mean square errors (RMSEs) are less than 0.037% for Pr and Zr; the limits of detection (LODs) are less than 1000 ppm for Y, Pr, and Zr; and the LODs of Y, Pr, and Zr at 2.97 m are higher than those at 1.89 m. Additionally, we tested the system on molten magnesium alloy in a magnesium alloy plant. The calibration results of the liquid magnesium alloy are not as favorable as those of the sampling solid magnesium alloys. In particular, the RSDs of the liquid magnesium alloy are approximately 20% for Pr and La. However, with future improvements in the experimental conditions, the developed system is promising for the in situ analysis of molten magnesium alloy.

参考文献 | 相关文章 | 多维度评价
Transport in graphene nanostructures
Christoph Stampfer, Stefan Fringes, Johannes Güttinger, Francoise Molitor, Christian Volk, Bernat Terrés, Jan Dauber, Stephan Engels, Stefan Schnez, Arnhild Jacobsen, Susanne Droscher, Thomas Ihn, Klaus Ensslin
Frontiers of Physics    2011, 6 (3): 271-293.
摘要   HTML   PDF (1095KB)

Graphene nanostructures are promising candidates for future nanoelectronics and solid-state quantum information technology. In this review we provide an overview of a number of electron transport experiments on etched graphene nanostructures. We briefly revisit the electronic properties and the transport characteristics of bulk, i.e., two-dimensional graphene. The fabrication techniques for making graphene nanostructures such as nanoribbons, single electron transistors and quantum dots, mainly based on a dry etching “paper-cutting” technique are discussed in detail. The limitations of the current fabrication technology are discussed when we outline the quantum transport properties of the nanostructured devices. In particular we focus here on transport through graphene nanoribbons and constrictions, single electron transistors as well as on graphene quantum dots including double quantum dots. These quasi-one-dimensional (nanoribbons) and quasi-zero-dimensional (quantum dots) graphene nanostructures show a clear route of how to overcome the gapless nature of graphene allowing the confinement of individual carriers and their control by lateral graphene gates and charge detectors. In particular, we emphasize that graphene quantum dots and double quantum dots are very promising systems for spin-based solid state quantum computation, since they are believed to have exceptionally long spin coherence times due to weak spin–orbit coupling and weak hyperfine interaction in graphene.

参考文献 | 相关文章 | 多维度评价
Review of borophene and its potential applications
Zhi-Qiang Wang, Tie-Yu Lü, Hui-Qiong Wang, Yuan Ping Feng, Jin-Cheng Zheng
Frontiers of Physics    2019, 14 (3): 33403-null.
摘要   PDF (16562KB)

Since two-dimensional boron sheet (borophene) synthesized on Ag substrates in 2015, research on borophene has grown fast in the fields of condensed matter physics, chemistry, material science, and nanotechnology. Due to the unique physical and chemical properties, borophene has various potential applications. In this review, we summarize the progress on borophene with a particular emphasis on the recent advances. First, we introduce the phases of borophene by experimental synthesis and theoretical predictions. Then, the physical and chemical properties, such as mechanical, thermal, electronic, optical and superconducting properties are summarized. We also discuss in detail the utilization of the borophene for wide ranges of potential application among the alkali metal ion batteries, Li-S batteries, hydrogen storage, supercapacitor, sensor and catalytic in hydrogen evolution, oxygen reduction, oxygen evolution, and CO2 electroreduction reaction. Finally, the challenges and outlooks in this promising field are featured on the basis of its current development.

参考文献 | 相关文章 | 多维度评价
Laser-induced breakdown spectroscopy in China
Zhe Wang, Ting-Bi Yuan, Zong-Yu Hou, Wei-Dong Zhou, Ji-Dong Lu, Hong-Bin Ding, Xiao-Yan Zeng
Frontiers of Physics    2014, 9 (4): 419-438.
摘要   PDF (325KB)

Laser-induced breakdown spectroscopy (LIBS) has been regarded as a future superstar for chemical analysis for years due to its unique features such as little or no sample preparation, remote sensing, and fast and multi-element analysis. Chinese LIBS community is one of the most dynamically developing communities in the World. The aim of the work is to inspect what have been done in China for LIBS development and, based on the understanding of the overall status, to identify the challenges and opportunities for the future development. In this paper, the scientific contributions from Chinese LIBS community are reviewed for the following four aspects: fundamentals, instrumentation, data processing and modeling, and applications; and the driving force of LIBS development in China is analyzed, the critical issues for successful LIBS application are discussed, and in our opinion, the potential direction to improve the technology and to realize large scale commercialization in China is proposed.

参考文献 | 相关文章 | 多维度评价
Relativistic quantum effects of Dirac particles simulated by ultracold atoms
Dan-wei Zhang (张丹伟), Zi-dan Wang (汪子丹), Shi-liang Zhu (朱诗亮)
Frontiers of Physics    2012, 7 (1): 31-53.
摘要   HTML   PDF (810KB)

Quantum simulation is a powerful tool to study a variety of problems in physics, ranging from high-energy physics to condensed-matter physics. In this article, we review the recent theoretical and experimental progress in quantum simulation of Dirac equation with tunable parameters by using ultracold neutral atoms trapped in optical lattices or subject to light-induced synthetic gauge fields. The effective theories for the quasiparticles become relativistic under certain conditions in these systems, making them ideal platforms for studying the exotic relativistic effects. We focus on the realization of one, two, and three dimensional Dirac equations as well as the detection of some relativistic effects, including particularly the well-known Zitterbewegung effect and Klein tunneling. The realization of quantum anomalous Hall effects is also briefly discussed.

参考文献 | 相关文章 | 多维度评价
Two-dimensional materials: Emerging toolkit for construction of ultrathin high-efficiency microwave shield and absorber
Mingjun Hu, Naibo Zhang, Guangcun Shan, Jiefeng Gao, Jinzhang Liu, Robert K. Y. Li
Frontiers of Physics    2018, 13 (4): 138113-.
摘要   PDF (39068KB)

Two-dimensional (2D) materials generally have unusual physical and chemical properties owing to the confined electro-strong interaction in a plane and can exhibit obvious anisotropy and a significant quantum-confinement effect, thus showing great promise in many fields. Some 2D materials, such as graphene and MXenes, have recently exhibited extraordinary electromagnetic-wave shielding and absorbing performance, which is attributed to their special electrical behavior, large specific surface area, and low mass density. Compared with traditional microwave attenuating materials, 2D materials have several obvious inherent advantages. First, similar to other nanomaterials, 2D materials have a very large specific surface area and can provide numerous interfaces for the enhanced interfacial polarization as well as the reflection and scattering of electromagnetic waves. Second, 2D materials have a particular 2D morphology with ultrasmall thickness, which is not only beneficial for the penetration and dissipation of electromagnetic waves through the 2D nanosheets, giving rise to multiple reflections and the dissipation of electromagnetic energy, but is also conducive to the design and fabrication of various well-defined structures, such as layer-by-layer assemblies, core–shell particles, and porous foam, for broadband attenuation of electromagnetic waves. Third, owing to their good processability, 2D materials can be integrated into various multifunctional composites for multimode attenuation of electromagnetic energy. In addition to behaving as microwave reflectors and absorbers, 2D materials can act as impedance regulators and provide structural support for good impedance matching and setup of the optimal structure. Numerous studies indicate that 2D materials are among the most promising microwave attenuation materials. In view of the rapid development and enormous advancement of 2D materials in shielding and absorbing electromagnetic wave, there is a strong need to summarize the recent research results in this field for presenting a comprehensive view and providing helpful suggestions for future development.

参考文献 | 相关文章 | 多维度评价
Topological nodal line semimetals predicted from first-principles calculations
Rui Yu,Zhong Fang,Xi Dai,Hongming Weng
Frontiers of Physics    2017, 12 (3): 127202-.
摘要   PDF (15818KB)

Topological semimetals are newly discovered states of quantum matter, which have extended the concept of topological states from insulators to metals and attracted great research interest in recent years. In general, there are three kinds of topological semimetals, namely Dirac semimetals, Weyl semimetals, and nodal line semimetals. Nodal line semimetals can be considered as precursor states for other topological states. For example, starting from such nodal line states, the nodal line structure might evolve into Weyl points, convert into Dirac points, or become a topological insulator by introducing the spin–orbit coupling (SOC) or mass term. In this review paper, we introduce theoretical materials that show the nodal line semimetal state, including the all-carbon Mackay–Terrones crystal (MTC), anti-perovskite Cu3PdN, pressed black phosphorus, and the CaP3 family of materials, and we present the design principles for obtaining such novel states of matter.

参考文献 | 相关文章 | 多维度评价
Laser cooling and trapping of ytterbium atoms
Xin-ye XU (徐信业), Wen-li WANG (王文丽), Qing-hong ZHOU (周庆红), Guo-hui LI (李国辉), Hai-ling JIANG (蒋海灵), Lin-fang CHEN (陈林芳), Jie YE (叶捷), Zhi-hong ZHOU (周志红), Yin CAI (蔡寅), Hai-yao TANG (唐海瑶), Min ZHOU (周敏)
Frontiers of Physics in China    2009, 4 (2): 160-164.
摘要   HTML   PDF (393KB)

The experiments on the laser cooling and trapping of ytterbium atoms are reported, including the two-dimensional transversal cooling, longitudinal velocity Zeeman deceleration, and a magneto-optical trap with a broadband transition at a wavelength of 399 nm. The magnetic field distributions along the axis of a Zeeman slower were measured and in a good agreement with the calculated results. Cold ytterbium atoms were produced with a number of about 107 and a temperature of a few milli-Kelvin. In addition, using a 556-nm laser, the excitations of cold ytterbium atoms at 1S0-3P1 transition were observed. The ytterbium atoms will be further cooled in a 556-nm magneto-optical trap and loaded into a three-dimensional optical lattice to make an ytterbium optical clock.

参考文献 | 相关文章 | 多维度评价
Quantum dynamics in ultracold atomic physics
Qiong-Yi He, Margaret D. Reid, Bogdan Opanchuk, Rodney Polkinghorne, Laura E. C. Rosales-Zárate, Peter D. Drummond
Frontiers of Physics    2012, 7 (1): 16-30.
摘要   HTML   PDF (535KB)

We review recent developments in the theory of quantum dynamics in ultracold atomic physics, including exact techniques and methods based on phase-space mappings that are applicable when the complexity becomes exponentially large. Phase-space representations include the truncated Wigner, positive-P and general Gaussian operator representations which can treat both bosons and fermions. These phase-space methods include both traditional approaches using a phase-space of classical dimension, and more recent methods that use a non-classical phase-space of increased dimensionality. Examples used include quantum Einstein–Podolsky–Rosen (EPR) entanglement of a four-mode BEC, time-reversal tests of dephasing in single-mode traps, BEC quantum collisions with up to 106 modes and 105 interacting particles, quantum interferometry in a multi-mode trap with nonlinear absorption, and the theory of quantum entropy in phase-space. We also treat the approach of variational optimization of the sampling error, giving an elementary example of a nonlinear oscillator.

参考文献 | 相关文章 | 多维度评价
First-principle study on the optical response of phosphorene
Jia-He Lin, Hong Zhang, Xin-Lu Cheng
Frontiers of Physics    2015, 10 (4): 107301-null.
摘要   PDF (757KB)

The optical response of phosphorene nanostructures was studied using time-dependent density functional theory (TDDFT). Compared with the absorption spectrum of graphene, that of the phosphorene nanostructure exhibits high absorbance in the ultraviolet region, which indicates a high light absorptivity. In a low-energy resonance zone, a spectral band extends to the entire near-infrared regions. When the impulse excitation polarizes in the armchair-edge direction, the low-energy plasmon in a few-layer phosphorene nanostructure shows an apparent long-range charge-transfer excitation but is significantly less pronounced along the zigzag-edge direction. The edge configuration significantly affects the absorption spectrum of monolayer phosphorene nanostructures. The armchair-edge and the zigzag-edge serve different functions in the absorption spectrum. Moreover, the absorption spectrum of the few-layer phosphorene nanostructure changes with the number of layers when the impulse excitation polarizes in the armchair-edge direction. In addition, the change in the low-energy resonance zone is significantly different from that in the high-energy resonance zone.

参考文献 | 相关文章 | 多维度评价
Semiclassical dynamics and nonlinear charge current
Yang Gao
Frontiers of Physics    2019, 14 (3): 33404-null.
摘要   PDF (1755KB)

Electron conductivity is an important material property that can provide a wealth of information about the underlying system. Especially, the response of the conductivity with respect to electromagnetic fields corresponds to various nonlinear charge currents, which have distinct symmetry requirements and hence can be used as efficient probes of different systems. To help the band-structure engineering of such nonlinear currents, a universal treatment of electron dynamics up to second order expressed in the basis of the unperturbed states are highly useful. In this work, we review the general semiclassical framework of the nonlinear charge currents.

参考文献 | 相关文章 | 多维度评价
A precision analysis and determination of the technical requirements of an atom interferometer for gravity measurement
Zhao-ying WANG (王兆英), Tao CHEN (陈涛), Xiao-long WANG (王肖隆), Zhang ZHANG (张璋), Yun-fei XU (徐云飞), Qiang LIN (林强)
Frontiers of Physics in China    2009, 4 (2): 174-178.
摘要   HTML   PDF (395KB)

The influence of the wave-front curvature of Raman pulses on the measurement precision of gravitational acceleration in atom interferometry is analysed by the method of a transmission matrix. It is shown that the measurement precision of gravitational acceleration is largely dependent on the spot size of the Raman pulse, the temporal interval between Raman pulses and the optical path difference of the two counter-propagating Raman pulses. Moreover, the influence of Doppler frequency shift on the precision is discussed. In order to get a certain measurement precision, the requirement for the accuracy of frequency scanning of the Raman pulse to compensate for the Doppler frequency shift is obtained.

参考文献 | 相关文章 | 多维度评价
Nanophotonics in China: Overviews and highlights
Zhi-Yuan Li
Frontiers of Physics    2012, 7 (6): 601-631.
摘要   HTML   PDF (394KB)

The major purpose of this paper is to present a brief overview of the history and the current status of nanophotonics research in China, and to highlight some research results in the past years made by the Chinese nanophotonics communities. I will first briefly introduce the principles of nanophotonics and several of its major disciplines including photonic crystals, plasmonics and metamaterials, and related artificial acoustic structures. Then I will highlight some major progresses made by Chinese research groups in these areas with the selection made merely based on my personal taste. The aim is to let these results better known and appreciated by researchers in the Chinese communities of nanophotonics and related areas, and provide better opportunities of researchers in different areas to have more communications. I also hope that this brief introduction will help to make a better bridge to connect Chinese nanophotonics communities with the broader communities in the world.

参考文献 | 相关文章 | 多维度评价
The art of designing carbon allotropes
Run-Sen Zhang, Jin-Wu Jiang
Frontiers of Physics    2019, 14 (1): 13401-.
摘要   PDF (7542KB)

Stimulated by the success of graphene and diamond, a variety of carbon allotropes have been discovered in recent years in either two-dimensional or three-dimensional configurations. Although these emerging carbon allotropes share some common features, they have certain different and novel mechanical or physical properties. In this review, we present a comparative survey of some of the major properties of fifteen newly discovered carbon allotropes. By comparing their structural topology, we propose a general route for designing most carbon allotropes from two mother structures, namely, graphene and diamond. Furthermore, we discuss several future prospects as well as current challenges in designing new carbon allotropes.

参考文献 | 相关文章 | 多维度评价
Carrier balance and linear magnetoresistance in type-II Weyl semimetal WTe2
Xing-Chen Pan,Yiming Pan,Juan Jiang,Huakun Zuo,Huimei Liu,Xuliang Chen,Zhongxia Wei,Shuai Zhang,Zhihe Wang,Xiangang Wan,Zhaorong Yang,Donglai Feng,Zhengcai Xia,Liang Li,Fengqi Song,Baigeng Wang,Yuheng Zhang,Guanghou Wang
Frontiers of Physics    2017, 12 (3): 127203-.
摘要   PDF (3544KB)

Unsaturated magnetoresistance (MR) has been reported in type-II Weyl semimetal WTe2, manifested as a perfect compensation of opposite carriers. We report linear MR (LMR) in WTe2 crystals, the onset of which was identified by constructing the MR mobility spectra for weak fields. The LMR further increased and became dominant for fields stronger than 20 T, while the parabolic MR gradually decayed. The LMR was also observed in high-pressure conditions.

参考文献 | 相关文章 | 多维度评价
Graphene based functional devices: A short review
Rong Wang, Xin-Gang Ren, Ze Yan, Li-Jun Jiang, Wei E. I. Sha, Guang-Cun Shan
Frontiers of Physics    2019, 14 (1): 13603-.
摘要   PDF (27911KB)

Graphene is an ideal 2D material system bridging electronic and photonic devices. It also breaks the fundamental speed and size limits by electronics and photonics, respectively. Graphene offers multiple functions of signal transmission, emission, modulation, and detection in a broad band, high speed, compact size, and low loss. Here, we have a brief view of graphene based functional devices at microwave, terahertz, and optical frequencies. Their fundamental physics and computational models were discussed as well.

参考文献 | 相关文章 | 多维度评价
Progress on tilted axis cranking covariant density functional theory for nuclear magnetic and antimagnetic rotation
Jie Meng (孟杰), Jing Peng (彭婧), Shuang-Quan Zhang (张双全), Peng-Wei Zhao (赵鹏巍)
Frontiers of Physics    2013, 8 (1): 55-79.
摘要   HTML   PDF (1056KB)

Magnetic rotation and antimagnetic rotation are exotic rotational phenomena observed in weakly deformed or near-spherical nuclei, which are respectively interpreted in terms of the shears mechanism and two shearslike mechanism. Since their observations, magnetic rotation and antimagnetic rotation phenomena have been mainly investigated in the framework of tilted axis cranking based on the pairing plus quadrupole model. For the last decades, the covariant density functional theory and its extension have been proved to be successful in describing series of nuclear ground-states and excited states properties, including the binding energies, radii, single-particle spectra, resonance states, halo phenomena, magnetic moments, magnetic rotation, low-lying excitations, shape phase transitions, collective rotation and vibrations, etc. This review will mainly focus on the tilted axis cranking covariant density functional theory and its application for the magnetic rotation and antimagnetic rotation phenomena.

参考文献 | 相关文章 | 多维度评价
Nanomaterials for electrochemical energy storage
Nian Liu, Weiyang Li, Mauro Pasta, Yi Cui
Frontiers of Physics    2014, 9 (3): 323-350.
摘要   PDF (2051KB)

The development of nanotechnology in the past two decades has generated great capability of controlling materials at the nanometer scale and has enabled exciting opportunities to design materials with desirable electronic, ionic, photonic, and mechanical properties. This development has also contributed to the advance in energy storage, which is a critical technology in this century. In this article, we will review how the rational design of nanostructured materials has addressed the challenges of batteries and electrochemical capacitors and led to high-performance electrochemical energy storage devices. Four specific material systems will be discussed: i) nanostructured alloy anodes for Li-batteries, ii) nanostructured sulfur cathodes for Li-batteries, iii) nanoporous openframework battery electrodes, and iv) nanostructured electrodes for electrochemical capacitors.

参考文献 | 相关文章 | 多维度评价
Fermion dynamical symmetry and strongly-correlated electrons: A comprehensive model of high-temperature superconductivity
Mike Guidry, Yang Sun, Lian-Ao Wu, Cheng-Li Wu
Frontiers of Physics    2020, 15 (4): 43301-null.
摘要   PDF (5356KB)

We review application of the SU(4) model of strongly-correlated electrons to cuprate and iron-based superconductors. A minimal self-consistent generalization of BCS theory to incorporate antiferromagnetism on an equal footing with pairing and strong Coulomb repulsion is found to account systematically for the major features of high-temperature superconductivity, with microscopic details of the parent compounds entering only parametrically. This provides a systematic procedure to separate essential from peripheral, suggesting that many features exhibited by the high-Tc data set are of interest in their own right but are not central to the superconducting mechanism. More generally, we propose that the surprisingly broad range of conventional and unconventional superconducting and superfluid behavior observed across many fields of physics results from the systematic appearance of similar algebraic structures for the emergent effective Hamiltonians, even though the microscopic Hamiltonians of the corresponding parent states may differ radically from each other.

参考文献 | 相关文章 | 多维度评价
Quantum transport in topological semimetals under magnetic fields
Hai-Zhou Lu,Shun-Qing Shen
Frontiers of Physics    2017, 12 (3): 127201-.
摘要   PDF (1444KB)

Topological semimetals are three-dimensional topological states of matter, in which the conduction and valence bands touch at a finite number of points, i.e., the Weyl nodes. Topological semimetals host paired monopoles and antimonopoles of Berry curvature at the Weyl nodes and topologically protected Fermi arcs at certain surfaces. We review our recent works on quantum transport in topological semimetals, according to the strength of the magnetic field. At weak magnetic fields, there are competitions between the positive magnetoresistivity induced by the weak anti-localization effect and negative magnetoresistivity related to the nontrivial Berry curvature. We propose a fitting formula for the magnetoconductivity of the weak anti-localization. We expect that the weak localization may be induced by inter-valley effects and interaction effect, and occur in double-Weyl semimetals. For the negative magnetoresistance induced by the nontrivial Berry curvature in topological semimetals, we show the dependence of the negative magnetoresistance on the carrier density. At strong magnetic fields, specifically, in the quantum limit, the magnetoconductivity depends on the type and range of the scattering potential of disorder. The high-field positive magnetoconductivity may not be a compelling signature of the chiral anomaly. For long-range Gaussian scattering potential and half filling, the magnetoconductivity can be linear in the quantum limit. A minimal conductivity is found at the Weyl nodes although the density of states vanishes there.

参考文献 | 相关文章 | 多维度评价
Negative magnetoresistance in Weyl semimetals NbAs and NbP: Intrinsic chiral anomaly and extrinsic effects
Yupeng Li,Zhen Wang,Pengshan Li,Xiaojun Yang,Zhixuan Shen,Feng Sheng,Xiaodong Li,Yunhao Lu,Yi Zheng,Zhu-An Xu
Frontiers of Physics    2017, 12 (3): 127205-.
摘要   PDF (1187KB)

Chiral anomaly-induced negative magnetoresistance (NMR) has been widely used as critical transport evidence for the existence of Weyl fermions in topological semimetals. In this mini-review, we discuss the general observation of NMR phenomena in non-centrosymmetric NbP and NbAs. We show that NMR can arise from the intrinsic chiral anomaly of Weyl fermions and/or extrinsic effects, such as the superimposition of Hall signals; field-dependent inhomogeneous current flow in the bulk, i.e., current jetting; and weak localization (WL) of coexistent trivial carriers. The WL-controlled NMR is heavily dependent on sample quality and is characterized by a pronounced crossover from positive to negative MR growth at elevated temperatures, resulting from the competition between the phase coherence time and the spin-orbital scattering constant of the bulk trivial pockets. Thus, the correlation between the NMR and the chiral anomaly need to be scrutinized without the support of complimentary techniques. Because of the lifting of spin degeneracy, the spin orientations of Weyl fermions are either parallel or antiparallel to the momentum, which is a unique physical property known as helicity. The conservation of helicity provides strong protection for the transport of Weyl fermions, which can only be effectively scattered by magnetic impurities. Chemical doping with magnetic and non-magnetic impurities is thus more convincing than the NMR method for detecting the existence of Weyl fermions.

参考文献 | 相关文章 | 多维度评价
Quadrupolar matter-wave soliton in two-dimensional free space
Jia-Sheng Huang, Xun-Da Jiang, Huai-Yu Chen, Zhi-Wei Fan, Wei Pang, Yong-Yao Li
Frontiers of Physics    2015, 10 (4): 100507-null.
摘要   PDF (353KB)

We study two-dimensional (2D) matter-wave solitons in the mean-field models formed by electric quadrupole particles with long-range quadrupole–quadrupole interaction (QQI) in 2D free space. The existence of 2D matter-wave solitons in the free space was predicted using the 2D Gross–Pitaevskii Equation (GPE). We find that the QQI solitons have a higher mass (smaller size and higher intensity) and stronger anisotropy than the dipole–dipole interaction (DDI) solitons under the same environmental parameters. Anisotropic soliton–soliton interaction between two identical QQI solitons in 2D free space is studied. Moreover, stable anisotropic dipole solitons are observed, to our knowledge, for the first time in 2D free space under anisotropic nonlocal cubic nonlinearity.

参考文献 | 相关文章 | 多维度评价
Simulating cyclotron-Bloch dynamics of a charged particle in a 2D lattice by means of cold atoms in driven quasi-1D optical lattices
Andrey R. Kolovsky
Frontiers of Physics    2012, 7 (1): 3-7.
摘要   HTML   PDF (236KB)

Quantum dynamics of a charged particle in a two-dimensional (2D) lattice subject to magnetic and electric fields is a rather complicated interplay between cyclotron oscillations (the case of vanishing electric field) and Bloch oscillations (zero magnetic field), details of which has not yet been completely understood. In the present work we suggest to study this problem by using cold atoms in optical lattices. We introduce a one-dimensional (1D) model which can be easily realized in laboratory experiments with quasi-1D optical lattices and show that this model captures many features of the cyclotron-Bloch dynamics of the quantum particle in 2D square lattices.

参考文献 | 相关文章 | 多维度评价
Effective models for nearly ideal Dirac semimetals
Feng Tang, Xiangang Wan
Frontiers of Physics    2019, 14 (4): 43603-null.
摘要   PDF (3214KB)

Topological materials (TMs) have gained intensive attention due to their novel behaviors compared with topologically trivial materials. Among various TMs, Dirac semimetal (DSM) has been studied extensively. Although several DSMs have been proposed and verified experimentally, the suitable DSM for realistic applications is still lacking. Thus finding ideal DSMs and providing detailed analyses to them are of both fundamental and technological importance. Here, we sort out 8 (nearly) ideal DSMs from thousands of topological semimetals in Nature 566(7745), 486 (2019). We show the concrete positions of the Dirac points in the Brillouin zone for these materials and clarify the symmetryprotection mechanism for these Dirac points as well as their low-energy effective models. Our results provide a useful starting point for future study such as topological phase transition under strain and transport study based on these effective models. These DSMs with high mobilities are expected to be applied in fabrication of functional electronic devices.

参考文献 | 相关文章 | 多维度评价
Graphene and other two-dimensional materials
Kostya S. Novoselov, Daria V. Andreeva, Wencai Ren, Guangcun Shan
Frontiers of Physics    2019, 14 (1): 13301-.
摘要   PDF (558KB)
参考文献 | 相关文章 | 多维度评价