Select
Correspondence between quantum-optical transform and classical-optical transform explored by developing Dirac’s symbolic method
Hong-yi Fan, Li-yun Hu
Frontiers of Physics. 2012, 7 (3 ): 261-310.
https://doi.org/10.1007/s11467-011-0206-z
By virtue of the new technique of performing integration over Dirac’s ket–bra operators, we explore quantum optical version of classical optical transformations such as optical Fresnel transform, Hankel transform, fractional Fourier transform, Wigner transform, wavelet transform and Fresnel–Hadmard combinatorial transform etc. In this way one may gain benefit for developing classical optics theory from the research in quantum optics, or vice-versa. We cannot only find some new quantum mechanical unitary operators which correspond to the known optical transformations, deriving a new theorem for calculating quantum tomogram of density operators, but also can reveal some new classical optical transformations. For examples, we find the generalized Fresnel operator (GFO) to correspond to the generalized Fresnel transform (GFT) in classical optics. We derive GFO’s normal product form and its canonical coherent state representation and find that GFO is the loyal representation of symplectic group multiplication rule. We show that GFT is just the transformation matrix element of GFO in the coordinate representation such that two successive GFTs is still a GFT. The ABCD rule of the Gaussian beam propagation is directly demonstrated in the context of quantum optics. Especially, the introduction of quantum mechanical entangled state representations opens up a new area in finding new classical optical transformations. The complex wavelet transform and the condition of mother wavelet are studied in the context of quantum optics too. Throughout our discussions, the coherent state, the entangled state representation of the two-mode squeezing operators and the technique of integration within an ordered product (IWOP) of operators are fully used. All these have confirmed Dirac’s assertion: “...for a quantum dynamic system that has a classical analogue, unitary transformation in the quantum theory is the analogue of contact transformation in the classical theory”.
参考文献 |
相关文章 |
多维度评价
Select
Doppler-free spectroscopy of rubidium atoms driven by a control laser
Zheng Tan(谭政), Xiu-chao Zhao (赵修超), Yong Cheng (程雍), Xian-ping Sun (孙献平), Jun Luo (罗军), Xin Zhou (周欣), Jin Wang (王谨), Ming-sheng Zhan (詹明生)
Frontiers of Physics. 2012, 7 (3 ): 311-314.
https://doi.org/10.1007/s11467-011-0192-1
A scheme of Doppler-free spectroscopy is experimentally demonstrated with a co-propagating control laser locking to an atomic hyperfine transition, and the differential transmission of the probe and the reference laser is detected. Crossover resonances are eliminated by selecting the class of atoms with zero velocity in the direction of beam propagation. In addition, the sub-Doppler spectrum experiences optical gain compared to the conventional saturated-absorption spectrum as a result of optical pumping.
参考文献 |
相关文章 |
多维度评价
Select
Electronic and optical properties of semiconductor and graphene quantum dots
Wei-dong Sheng, Marek Korkusinski, Alev Devrim Gü?lü, Michal Zielinski, Pawel Potasz, Eugene S. Kadantsev, Oleksandr Voznyy, Pawel Hawrylak
Frontiers of Physics. 2012, 7 (3 ): 328-352.
https://doi.org/10.1007/s11467-011-0200-5
Our recent work on the electronic and optical properties of semiconductor and graphene quantum dots is reviewed. For strained self-assembled InAs quantum dots on GaAs or InP substrate atomic positions and strain distribution are described using valence-force field approach and continuous elasticity theory. The strain is coupled with the effective mass, k · p , effective bond-orbital and atomistic tight-binding models for the description of the conduction and valence band states. The single-particle states are used as input to the calculation of optical properties, with electronelectron interactions included via configuration interaction (CI) method. This methodology is used to describe multiexciton complexes in quantum dot lasers, and in particular the hidden symmetry as the underlying principle of multiexciton energy levels, manipulating emission from biexcitons for entangled photon pairs, and optical control and detection of electron spins using gates. The self-assembled quantum dots are compared with graphene quantum dots, one carbon atom-thick nanostructures. It is shown that the control of size, shape and character of the edge of graphene dots allows to manipulate simultaneously the electronic, optical, and magnetic properties in a single material system.
参考文献 |
相关文章 |
多维度评价
Select
First principles study on magnetic and electronic properties with rare-earth atoms doped SWCNTs
Shun-li Yue, Hong Zhang
Frontiers of Physics. 2012, 7 (3 ): 353-359.
https://doi.org/10.1007/s11467-011-0209-9
The adsorptions of rare-earth (RE) atoms on (6, 0) and (8, 0) single-walled carbon nanotubes (SWCNTs) have been investigated by using the first-principles pseudopotential plane wave method within density functional theory (DFT). The binding energy, Mulliken charge, magnetic properties, band structure and DOS were calculated and analyzed. Most of RE atoms including Nd, Sm and Eu have a magnetic ground state with a significant magnetic moment. Some electrons transfer between RE-5d, 6s and C-2p orbitals. Owing to the curvature effect, the values of binding energy for RE atoms doped (6, 0) SWCNT are lower than those of the same atoms on (8, 0) SWCNT. The pictures of DOS show that hybridizations between RE-5d, 6s states and C-2p orbitals and between RE-4f and C-2p orbitals appear near the Fermi level. Results indicate that the properties of SWCNTs can be modified by the adsorptions of RE atoms.
参考文献 |
相关文章 |
多维度评价
Select
A novel snowdrift game model with edge weighting mechanism on the square lattice
Juan-juan Zhang (张娟娟), Hong-yun Ning (宁红云), Zi-yu Yin (银子瑜), Shi-wen Sun (孙世温), Li Wang (王莉), Jun-qing Sun (孙俊清), Cheng-yi Xia (夏承遗)
Frontiers of Physics. 2012, 7 (3 ): 366-372.
https://doi.org/10.1007/s11467-011-0208-x
We propose a novel snowdrift game model with edge weighting mechanism to explore the cooperative behaviors among the players on the square lattice. Based on the assumption of three types of weight distribution including uniform, exponential and power-law schemes, the cooperation level is largely boosted in contrast with the traditional snowdrift game on the unweighted square lattice. Extensive numerical simulations indicate that the fraction of cooperators greatly augments, especially for the intermediate range of cost-to-benefit ratio r . Furthermore, we investigate how the cooperative behaviors are affected by the undulation amplitude of weight distribution and noise strength of strategy selection, respectively. The simulation results will be conducive to further understanding and analyzing the emergence of cooperation, which is a ubiquitous phenomenon in social and biological science.
参考文献 |
相关文章 |
多维度评价
11篇文章