Open quantum system description of singlet-triplet qubits in quantum dots

Abstract

We develop a theoretical model to describe the dissipative dynamics of singlet-triplet (S-T_0) qubits in GaAs quantum dots. Using the concurrence experimentally obtained as a guide, we show that each logical qubit is coupled to its own environment because the decoherence effect can be described by independent dephasing channels. Given the correct description of the environment, we study the dynamics of concurrence as a function of the temperature, the constant coupling between the system and the environment, the preparation time, and the exchange coupling. Although the reduction of the environment coupling constant modifies the entanglement dynamics, we demonstrate that temperature emerges as a crucial variable and a variation of millikelvins significantly modifies the generation of entangled states. Furthermore, we show that the exchange coupling together with the preparation time strongly affects the entanglement dissipative dynamics.

This version provides a description of the decoherence mechanism that is completely different from the published version. For a closer version see arXiv: 1701.03169

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Cited by in corpus (5)

• Quantum dephasing induced by non-Markovian random telegraph noise
• Effects of charge noise on a pulse-gated singlet-triplet $S-T_{-}$ qubit
• Application of the Landau-Zener-Stueckelberg-Majorana dynamics in an electrically driven flip of a hole spin
• Non-Markovian memory in a measurement-based quantum computer
• Spin-qubit noise spectroscopy from randomized benchmarking by supervised learning