Resonant tunneling and enhanced Goos–Hänchen shift in a graphene double velocity barrier structure

Resonant transmission and Goos–Hänchen (GH) shift for Dirac fermion beams tunneling through graphene double velocity barrier structures (DVBs) are investigated theoretically. Analytical and numerical results demonstrate that strong resonant tunneling effect occurs in this structure and is highly dependent on the incident angle and the structure of velocity barriers. The resonant tunneling in graphene DVBs belongs to the Fabry–Pérot resonance and leads to oscillated conduction at wide energy range. It is also found that GH shifts in this structure can be enhanced by the resonant tunneling and multi-GH shift peaks with giant magnitudes can occur at these resonant energy positions. These special properties of GH shifts in graphene DVBs may have good application in lateral manipulation of electron beams and valley or spin beam splitter.     

Nonlinear Goos–Hänchen shifts of reflected light from inhomogeneous Kerr-like slabs

We investigate the Goos–Hänchen (GH) shifts of reflected light from Kerr-like slabs, whose permittivities are inhomogeneous in space as well as light intensity dependent. The GH shifts exhibit bistable, multivalued properties or a more complicated hysteretic response to the input light intensity, and the different spatial dependences of the permittivity have a great effect on the hysteretic response. The bistable or multivalued GH shifts can be modulated by various parameters, such as the angle of incidence and the thickness of slab.     

全反射地震P波的Goos-Hanchen效应定量分析

利用反射波相角推导出了反射P波在反射界面的横向偏移和横向偏移渡越时间,讨论了Goos-Hanchen效应对P波正常时差所造成的影响。结果发现,对于掠入射波或当入射角在临界角附近时,反射P波的Goos-Hanchen效应较为明显,故在实际的地震资料处理中应进行横向偏移效应的误差校正。     

Goos–Hänchen like shifts in graphene double barriers

We study the Goos–Hänchen like shifts for Dirac fermions in graphene scattered by double barrier structures. After obtaining the solution for the energy spectrum, we use the boundary conditions to explicitly determine the Goos–Hänchen like shifts and the associated transmission probability. We analyze these two quantities at resonances by studying their main characteristics as a function of the energy and electrostatic potential parameters. To check the validity of our computations we recover previous results obtained for a single barrier under appropriate limits.     

Zero,positive and negative quantum Goos–Hänchen shifts in graphene barrier with vertical magnetic field

We have explored the zero, positive and negative quantum Goos–Hänchen (GH) shifts of the transmitted Dirac carriers in graphene through a potential barrier with vertical magnetic field. Numerical results show that only one energy position at the zero GH shift exists and is highly dependent on the y-directional wave vector, the energy gap, the magnetic field and the potential. The positive and negative GH shifts happen when the incident energy is more and less than the energy position at the zero GH shift, respectively. In addition, we found that there are two values of potential at the zero GH shifts, where a potential window can always keep the positive GH shifts. These results may be useful in designing a graphene-based valley or spin splitter as well as manipulating the electrons and holes in graphene nanostructure.     

基于古斯汉欣效应的皮米级位移传感器的实验研究

本文利用光束在对称双面金属包覆波导表面反射时古斯一汉欣（Goos—Hanchen）位移具有极大的增强效应,提出一种灵敏度的极高的新型位移传感器。与传统的光强传感器相比,这种传感器消除了光源的能量波动对灵敏度的影响,从而能够观测更加微小的位移变化。在实验上实现了8pm微小位移传感。研究表明,该器件测量实时性强、精确度较高...     

Lateral shift in a spin-orbit-coupling modulated magnetic-barrier nanostructure

Spin-dependent Goos–Hänchen（GH）effect of the electron in a magnetic barrier nanostructure modulated by the spin-orbit coupling (SOC) is investigated. Two kinds of intrinsic SOCs (Rashba and Dresselhaus types) are taken into account, and spin-dependent lateral shifts are obtained by the transfer matrix method and the stationary phase approximation. The spin-dependent lateral shift is found to be related closely to the SOC. Both magnitude and sign of the spin-polarised lateral shift can be controlled by properly adjusting the strength of Rashba or Dresselhaus SOC. These interesting features can provide an alternative approach to manipulate spin-polarised electrons in the semiconductor, and such a nanostructure can serve as a controllable spatial spin splitter for spintronics applications.     

Implications of spectral hole burning on the manipulation of spatial Goos–Hänchen shift in an atomic cell

We present a new scheme to report on Goos–Hänchen (GH) shift experienced by the Gaussian light beam interacting with an optical cavity filled with four-level sodium atomic medium in the spectral hole burning region with and without Doppler broadening effect. Theoretical atomic density-matrix formalism is employed to obtain the susceptibility of atomic medium while the stationary-phase-theory is used to compute the GH shift in the reflected and transmitted probe beams subjected to control fields. A steep normal slope of dispersion is observed with a maximum and zero probability of transmission and reflection coefficients, respectively, at the regions of the spectral holes burning. In the normal dispersion spectrum at the region of spectral hole burning, positive and negative GH shift is observed, respectively, in the transmitted and reflected light beams. However, at anomalous dispersive regions negative GH shift in the transmission beam and positive GH shift in the reflection beam is observed. The reflection and transmission coefficients as well as the spatial GH shift are the functions of probe detuning, collective phase of control fields, beam incident angle and inverse Doppler broadening effect in the spectral hole burning region. The position and number of spectral holes also depend on the same spectral parametrs as stated above. The study is expected to be useful for optoelectronic devices and optical-clocking applications.