scholarly journals Quantum computational speed of a nanowires system with Rashba interaction in the presence of a magnetic field

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rabie I. Mohamed ◽  
Manal G. Eldin ◽  
Ahmed Farouk ◽  
A. A. Ramadan ◽  
M. Abdel-Aty

AbstractThe present research is designed to examine the dynamic of the quantum computational speed in a nanowire system through the orthogonality speed when three distinct types of magnetic fields are applied: the strong magnetic field, the weak magnetic field, and no magnetic field. Moreover, we investigate the action of the magnetic fields, the spin-orbit coupling, and the system’s initial states on the orthogonality speed. The observed results reveal that a substantial correlation between the intensity of the spin-orbit coupling and the dynamics of the orthogonality speed, where the orthogonality speed decreasing as the spin-orbit coupling increases. Furthermore, the initial states of the nanowire system are critical for regulating the speed of transmuting the information and computations.

2021 ◽  
Author(s):  
Elham Sadeghi ◽  
Hamed Rezania

Abstract In this paper, the transport properties of a two-dimensional Lieb lattice that is a line-centered square lattice are investigated in the presence of magnetic field and spin-orbit coupling. Specially, we address the temperature dependence of electrical and thermal conductivities as well as Seebeck coefficient due to spin-orbit interaction. We have exploited Green’s function approach in order to study thermoelectric and transport properties of Lieb lattice in the context of Kane-Mele model Hamiltonian. The results for Seebeck coefficient show the sign of thermopower is positive in the presence of spin-orbit coupling. Also the temperature dependence of transport properties indicates that the increase of spin-orbit coupling leads to decrease thermal conductivity however the decrease of gap 1 parameter causes the reduction of thermal conductivity. There is a peak in temperature dependence of thermal conductivity for all values of magnetic fields and spin-orbit coupling strengths. Both electrical and thermal conductivities increase with increasing the temperature at low amounts of temperature due to the increasing of transition rate of charge carriers and excitation of them to the conduction bands. Also we have studied the temperature dependence of spin susceptibility of Lieb monolayer due to both spin orbit coupling and magnetic field factors in details.


2014 ◽  
Vol 28 (27) ◽  
pp. 1450185
Author(s):  
Wei Xin ◽  
Chao Han ◽  
Eerdunchaolu

On the basis of Lee–Low–Pines (LLP) unitary transformation, the influence of external magnetic field, Rashba spin–orbit coupling and quantum size effect on the ground-state interaction energy of strong-coupling magnetopolarons in quantum disks (QDs) is studied by using the Tokuda improved linear combine operator method. The results show that the ground-state interaction energy of magnetopolarons consists of four parts: the energy caused by the confinement potential of QDs, interaction energy between the electron and external magnetic field, electron and longitudinal-optical (LO) phonon interaction energy and additional term of Rashba effect originating from phonons. The electron–LO phonon interaction energy Ee- ph and additional term of Rashba effect are always negative; the absolute value |Ee- ph | increases with increasing transverse confinement strength ω0, cyclotron frequency of external magnetic field ωc and electron–LO phonon coupling strength α, but decreases with increasing the thickness of QDs L; the state properties of magnetopolarons are closely linked with the sign of the ground-state interaction energy of magnetopolarons E int and change of E int with ωc, ω0, α and L. In addition, the vibration frequency of magnetopolarons λ increases with increasing ωc, ω0 and α, but decreases with increasing L. For the ground state of magnetopolarons in QDs, the electron–LO phonon interaction plays a significant role, meanwhile, the influence of Rashba spin–orbit coupling effect cannot be ignored.


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