2008/06/02 by Zhen‐Gang Zhu, Zhen-Gang Zhu, Jamal Berakdar
Chemistry · Engineering · Physics and Astronomy · #Advancements in Semiconductor Devices and Circuit Design #Atomic physics #Chemistry #Condensed matter physics #Dipole #Electron #Non-equilibrium thermodynamics #Physics #Polarization (electrochemistry) #Quantum and electron transport phenomena #Quantum mechanics #Semiconductor Quantum Structures and Devices #Spin (aerodynamics) #Spin polarization #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevb.77.235438
published as Phys. Rev. B 77, 235438 (2008) · 24 pages, 8 figures. accepted for publication in Phys. Rev. B
arxiv created 2008/06/02 · openalex publication_date 2008/06/25 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We investigate the spin-dependent dynamical response of a quantum ring with a spin orbit (SO) interaction upon the application of linearly polarized, picosecond, asymmetric electromagnetic pulses. The oscillations of the generated dipole moment are sensitive to the parity of the occupation number in the ring and to the strength of the SO coupling. It is shown how the associated emission spectrum can be controlled via the pulse strength or a gate voltage. In addition, we inspect how a static magnetic flux can modify the nonequilibrium dynamics. In the presence of the SO interaction and for a paramagnetic ring, the applied pulse results in a spin-split, nonequilibrium local charge density. The resulting temporal spin polarization is directed perpendicular to the light-pulse-polarization axis and oscillates periodically with the frequency of the spin-split charge density. The spin-averaged, nonequilibrium charge-density possesses a left-right symmetry with respect to the pulse-polarization axis. The calculations presented here are applicable to nanometer rings fabricated in heterojuctions of III-V and II-VI semiconductors containing several hundreds of electrons.