Controllable quantum scars induced by spin-orbit couplings in quantum dots

TL;DR

This paper demonstrates how spin-orbit couplings in quantum dots induce controllable quantum scar states, linking classical chaos and quantum interference, with potential for precise external control and detection.

Contribution

It reveals the emergence and controllability of quantum scars induced by spin-orbit couplings in quantum dots, highlighting their robustness and classical-quantum connection.

Findings

Quantum scars appear quasi-periodically in eigenstates due to SOCs.

Equal Rashba and Dresselhaus SOCs eliminate classical chaos and quantum scars.

Quantum scars are robust and controllable via external gating.

Abstract

Spin-orbit couplings (SOCs), originating from the relativistic corrections in the Dirac equation, offer nonlinearity in the classical limit and are capable of driving chaotic dynamics. In a nanoscale quantum dot confined by a two-dimensional parabolic potential with SOCs, various quantum scar states emerge quasi-periodically in the eigenstates of the system, when the ratio of confinement energies in the two directions is nearly commensurable. The scars, displaying both quantum interference and classical trajectory features on the electron density, due to relativistic effects, serve as a bridge between the classical and quantum behaviors of the system. When the strengths of Rashba and Dresselhaus SOCs are identical, the chaos in the classical limit is eliminated as the classical Hamilton's equations become linear, leading to the disappearance of all quantum scar states. Importantly, the quantum scars induced by SOCs are robust against small perturbations of system parameters. With precise control achievable through external gating, the quantum scar induced by Rashba SOC is fully controllable and detectable.