Nonequilibrium stabilization of charge states in double quantum dots

2003/02/28 by Udo Hartmann, Frank K. Wilhelm
Computer Science · Mathematics · Physics and Astronomy · #Charge (physics) #Charge qubit #Coherence (philosophical gambling strategy) #Condensed matter physics #Dephasing #Hamiltonian (control theory) #Master equation #Mathematics #Non-equilibrium thermodynamics #Phase qubit #Physics #Quantum #Quantum Information and Cryptography #Quantum and electron transport phenomena #Quantum decoherence #Quantum dissipation #Quantum dot #Quantum mechanics #Qubit #Relaxation (psychology) #Semiconductor Quantum Structures and Devices #cond-mat.mes-hall #quant-ph

paper · pdf · doi:10.1103/physrevb.69.161309

published as Phys. Rev. B 69, 161309(R) (2004) · 5 pages, 5 figures

openalex publication_date 2004/04/28 · arxiv created 2004/04/29 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

We analyze the decoherence of charge states in double quantum dots due to cotunneling. The system is treated using the Bloch-Redfield generalized master equation for the Schrieffer-Wolff transformed Hamiltonian. We show that the decoherence, characterized through a relaxation \ensuremathτ_r and a dephasing time \ensuremathτ_\ensuremathφ, can be controlled through the external voltage and that the optimum point, where these times are maximum, is not necessarily in equilibrium. We outline the mechanism of this nonequilibrium-induced enhancement of lifetime and coherence. We discuss the relevance of our results for recent charge qubit experiments.

Citations

• Few-electron quantum dot circuit with integrated charge read out
• Charge-based quantum computing using single donors in semiconductors
• Relation between the Anderson and Kondo Hamiltonians
• Dynamics of the dissipative two-state system
• Scaling Theory of the Asymmetric Anderson Model
• Theoretical analysis of continuously driven dissipative solid-state qubits