Coexisting spin and Rabi oscillations at intermediate time regimes in electron transport through a photon cavity.

Vidar Gudmundsson,Valeriu Moldoveanu,Andrei Manolescu,Hallmann Gestsson,Chi-Shung Tang,Nzar Rauf Abdullah

doi:10.3762/bjnano.10.61

Abstract

In this work, we theoretically model the time-dependent transport through an asymmetric double quantum dot etched in a two-dimensional wire embedded in a far-infrared (FIR) photon cavity. For the transient and the intermediate time regimes, the current and the average photon number are calculated by solving a Markovian master equation in the dressed-states picture, with the Coulomb interaction also taken into account. We predict that in the presence of a transverse magnetic field the interdot Rabi oscillations appearing in the intermediate and transient regime coexist with slower non-equilibrium fluctuations in the occupation of states for opposite spin orientation. The interdot Rabi oscillation induces charge oscillations across the system and a phase difference between the transient source and drain currents. We point out a difference between the steady-state correlation functions in the Coulomb blocking and the photon-assisted transport regimes.

Highlights

Experimental [1,2,3,4,5,6] and theoretical [7,8,9,10,11] interest is growing in electron transport through semiconductor systems in photon cavities
The time-dependent electronic transport through a two-dimensional (2D) nanosystem patterned in a GaAs heterostructure, which is in turn embedded in a three-dimensional (3D) FIR photon cavity, generally displays three regimes: i) The switching transient regime in which electrons tunnel through the system but their interactions with the photons have not had time to affect the transport yet; ii) the intermediate regime during which the electron–photon coupling plays an important role in bringing the system to a steady state; and iii) the stationary regime with coexisting radiative transitions and photon-assisted tunneling [9]
In earlier publications we have shown how a Rabi oscillation can be detected in the transport of electrons through an electronic system in a 3D photon cavity, in the transient regime directly from the charge current [15], and in the steady state through the Fourier power spectrum of the current current correlation function [16]

Summary

Introduction

Experimental [1,2,3,4,5,6] and theoretical [7,8,9,10,11] interest is growing in electron transport through semiconductor systems in photon cavities. The photon energy = 0.343 meV coupling the two lowest one-electron states mostly localized in each quantum dot leads to a Rabi resonance showing up in non-integer values for the photon content of some states.

Results

Conclusion