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arXiv · 2106.01576

Real-time observation of charge-spin cooperative dynamics driven by a nonequilibrium phonon environment

Kazuyuki Kuroyama·Sadashige Matsuo·Jo Muramoto·Shunsuke Yabunaka·Sasha R. Valentin·Arne Ludwig·Andreas D. Wieck·Yasuhiro Tokura·Seigo Tarucha
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Abstract

Quantum dots are recognized as a suitable platform for studying thermodynamic phenomena involving single electronic charges and spins in nano-scale devices. However, such a thermodynamic system is usually driven by electron reservoirs at different temperatures, not by a lattice temperature gradient. We report on experimental observations of charge-spin cooperative dynamics in transitions of two-electron spin states in a GaAs double quantum dot located in a non-equilibrium phonon environment. Enhancements in the spin-flip processes are observed, originating from phonon excitation combined with the spin-orbit interaction. In addition, due to the spatial gradient of phonon density between the dots, the spin-flip rate during an inter-dot electron tunnel from a hot to a cold dot is more enhanced than in the other direction, resulting in accumulation of parallel spin states in the double dot.

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Kazuyuki Kuroyama, Sadashige Matsuo, Jo Muramoto, Shunsuke Yabunaka, Sasha R. Valentin, Arne Ludwig, Andreas D. Wieck, Yasuhiro Tokura, Seigo Tarucha. 2021-06-03. Real-time observation of charge-spin cooperative dynamics driven by a nonequilibrium phonon environment. https://doi.org/10.1103/physrevlett.129.095901

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