Manipulation of Single Electron Spin in a GaAs Quantum Dot through the Application of Geometric Phases: The Feynman Disentangling Technique
The spin of a single electron in an electrically defined quantum dot in a two-dimensional electron gas can be manipulated by moving the quantum dot adiabatically in a closed loop in the two-dimensional plane under the influence of applied gate potentials. In this paper we present analytical expressions and numerical simulations for the spin-flip probabilities during the adiabatic evolution in the presence of the Rashba and Dresselhaus linear spin-orbit interactions. We use the Feynman disentanglement technique to determine the non-Abelian Berry phase and we find exact analytical expressions for three special cases: (i) the pure Rashba spin-orbit coupling, (ii) the pure Dresselhause linear spin-orbit coupling, and (iii) the mixture of the Rashba and Dresselhaus spin-orbit couplings with equal strength. For a mixture of the Rashba and Dresselhaus spin-orbit couplings with unequal strengths, we obtain simulation results by solving numerically the Riccati equation originating from the disentangling procedure. We find that the spin-flip probability in the presence of the mixed spin-orbit couplings is generally larger than those for the pure Rashba case and for the pure Dresselhaus case, and that the complete spin-flip takes place only when the Rashba and Dresselhaus spin-orbit couplings are mixed symmetrically.
Prabhakar, Sanjay; Reynolds, James; Inomata, Akira; and Melnik, Roderick V.N., "Manipulation of Single Electron Spin in a GaAs Quantum Dot through the Application of Geometric Phases: The Feynman Disentangling Technique" (2010). Mathematics Faculty Publications. 33.
This article was originally published in Physical Review B, 82: 195306. © 2010 The American Physical Society.