Topologically protected Bell-cat states in a simple spin model
arXiv:2410.23532 · doi:10.1103/y4g4-bksr
Abstract
We consider the topological properties of the so-called central spin model that consists of identical spins coupled to a single distinguishable central spin which arises in physical systems such as circuit-QED and bosonic Josephson junctions coupled to an impurity atom. The model closely corresponds to the Su-Schrieffer-Heeger (SSH) model except that the chain of sites in the SSH model is replaced by a chain of states in Fock space specifying the magnetization. We find that the model accommodates topologically protected eigenstates that are `Bell-cat' states consisting of a Schrödinger cat state of the spins that is maximally entangled with the central spin, and show how this state can be adiabatically created and moved along the chain by driving the central spin. The Bell-cat states are visualized by plotting their Wigner function and we explore their robustness against random noise by solving the master equation for the density matrix. We also explain the essential topological difference between identical spins and the excitations of a bosonic mode.
12 pages, 8 figures,
References in corpus (33)
- Quantum information with continuous variables
- Direct Observation of Tunneling and Nonlinear Self-Trapping in a single Bosonic Josephson Junction
- Reconstruction of non-classical cavity field states with snapshots of their decoherence
- The Kerr-Cat Qubit: Stabilization, Readout, and Gates
- Classical bifurcation at the transition from Rabi to Josephson dynamics
- Experimental demonstration of a hyper-entangled ten-qubit Schrödinger cat state
- Non-Markovian dynamics in a spin star system: Exact solution and approximation techniques
- Exponential suppression of bit-flips in a qubit encoded in an oscillator
- Deterministic creation of entangled atom-light Schrödinger-cat states
- Consistency of the Adiabatic Theorem
- Schrödinger cat states of a 16-microgram mechanical oscillator
- A CNOT gate between multiphoton qubits encoded in two cavities
- Numerical modeling of the central spin problem using the spin coherent states P-representation
- Observation of quantum interference between separated mechanical oscillator wavepackets
- Spin-motion entanglement and state diagnosis with squeezed oscillator wavepackets
- Single-atom quantum probes for ultracold gases using nonequilibrium spin dynamics
- Swings and roundabouts: Optical Poincaré spheres for polarization and Gaussian beams
- Quantum spin dynamics of individual neutral impurities coupled to a Bose-Einstein condensate
- A bosonic Josephson junction controlled by a single trapped ion
- Modal Majorana sphere and hidden symmetries of structured-Gaussian beams
- Coherent and dephasing spectroscopy for single-impurity probing of an ultracold bath
- Quantum dynamics of an atomic double-well system interacting with a trapped ion
- Impurity in a bosonic Josephson junction: swallowtail loops, chaos, self-trapping and the poor man's Dicke model
- Impurity in a Bose-Einstein condensate in a double well
- Coherent single atom shuttle between two Bose-Einstein condensates
- A single fermion in a Bose Josephson Junction
- Impurity induced quantum chaos for an ultracold bosonic ensemble in a double-well
- A Quantum Top Inside a Bose Josephson Junction
- Compound atom-ion Josephson junction: Effects of finite temperature and ion motion
- Exactly solvable model behind Bose-Hubbard dimers, Ince-Gauss beams, and aberrated optical cavities
- Critical exponents for an impurity in a bosonic Josephson junction: Position measurement as a phase transition
- Density of states and quantum phase transition in the thermodynamic limit of the Mermin central-spin model
- Two-particle topological Thouless spin pump