Spontaneous Symmetry Breaking of Time-Reversal-Symmetry and Time-Crystal States in Chiral Atomic Systems
arXiv:2308.09559 · doi:10.1103/PhysRevB.108.235154
Abstract
We present a theoretical study of the interaction between an atom characterized by a degenerate ground state and a reciprocal environment, such as a semiconductor nanoparticle, without the presence of external bias. Our analysis reveals that the combined influence of the electron's intrinsic spin magnetic moment on the environment and the chiral atomic dipolar transitions may lead to either the spontaneous breaking of time-reversal symmetry or the emergence of time-crystal-like states with remarkably long relaxation times. The different behavior is ruled by the handedness of the precession motion of the atom's spin vector, which is induced by virtual chiral-dipolar transitions. Specifically, when the relative orientation of the precession angular velocity and the electron spin vector is as in a spinning top, the system manifests time-crystal-like states. Conversely, with the opposite relative orientation, the system experiences spontaneous symmetry breaking of time-reversal symmetry. Our findings introduce a novel mechanism for the spontaneous breaking of time-reversal symmetry in atomic systems, and unveil an exciting opportunity to engineer a nonreciprocal response at the nanoscale, exclusively driven by the quantum vacuum fluctuations.
62 pages
References in corpus (12)
- Chiral Quantum Optics
- Absence of Quantum Time Crystals
- All-Optical Routing of Single Photons by a One-Atom Switch Controlled by a Single Photon
- Quantum optical circulator controlled by a single chirally coupled atom
- Colloquium: Quantum and Classical Discrete Time Crystals
- Atomic spin-controlled non-reciprocal Raman amplification of fibre-guided light
- Coherent optical non-reciprocity in axisymmetric resonators
- Nonreciprocal and non-Hermitian material response inspired by semiconductor transistors
- Engineering transistor-like optical gain in two-dimensional materials with Berry curvature dipoles
- Mode softening in time-crystalline transitions of open quantum systems
- Casimir-Lifshitz Force for Nonreciprocal Media and Applications to Photonic Topological Insulators
- Spontaneous Rotational Symmetry Breaking in a Kramers Two-Level System