Phonon-induced dephasing of singlet-triplet superpositions in double quantum dots without spin-orbit coupling

Abstract

We show that singlet-triplet superpositions of two-electron spin states in a double quantum dot undergo a phonon-induced pure dephasing which relies only on the tunnel coupling between the dots and on the Pauli exclusion principle. As such, this dephasing process is independent of spin-orbit coupling or hyperfine interactions. The physical mechanism behind the dephasing is elastic phonon scattering, which persists to much lower temperatures than real phonon-induced transitions. Quantitative calculations performed for a lateral GaAs/AlGaAs gate-defined double quantum dot yield micro-second dephasing times at sub-Kelvin temperatures, which is consistent with experimental observations.

Extended version

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Cited by in corpus (15)

• Spin dynamics in semiconductors
• Exchange coupling in silicon quantum dots: Theoretical considerations for quantum computation
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• Phonon-assisted relaxation and tunneling in self-assembled quantum dot molecules
• Two-spin dephasing by electron-phonon interaction in semiconductor double quantum dots
• Microscopic models for charge-noise-induced dephasing of solid-state qubits
• Decoherence of an exchange qubit by hyperfine interaction
• Hyperfine interaction induced dephasing of coupled spin qubits in semiconductor double quantum dots
• Sudden death of effective entanglement
• Phonon-assisted relaxation and decoherence of singlet-triplet qubits in Si/SiGe quantum dots
• Phonon-induced decoherence of a charge quadrupole qubit
• Decoherence enhanced quantum measurement of a quantum dot spin qubit
• Phonon influence on the measurement of spin states in double quantum dots using the quantum point contact
• Harnessing spin-qubit decoherence to probe strongly-interacting quantum systems
• Revealing the internal spin dynamics in a double quantum dot by periodic voltage modulation