Unbalanced gain and loss in a quantum photonic system
arXiv:2307.13526 · doi:10.1088/2040-8986/ace5be
Abstract
Theories in physics can provide a kind of map of the physical system under investigation, showing all of the possible types of behavior which may occur. Certain points on the map are of greater significance than others, because they describe how the system responds in a useful or interesting manner. For example, the point of resonance is of particular importance when timing the pushes onto a person sat on a swing. More sophisticatedly, so-called exceptional points have been shown to be significant in optical systems harbouring both gain and loss, as typically described by non-Hermitian Hamiltonians. However, expressly quantum points of interest -- be they exceptional points or otherwise -- arising in quantum photonic systems have been far less studied. Here we consider a paradigmatic model: a pair of coupled qubits subjected to an unbalanced ratio of gain and loss. We mark on its map several flavours of both exceptional and critical points, each of which are associated with unconventional physical responses. In particular, we uncover the points responsible for characteristic spectral features and for the sudden loss of quantum entanglement in the steady state. Our results provide perspectives for characterizing quantum photonic systems beyond effective non-Hermitian Hamiltonians, and suggest a hierarchy of intrinsically quantum points of interest.
arXiv comment10 pages, 5 figures
References in corpus (53)
- Entanglement of Formation of an Arbitrary State of Two Qubits
- Real Spectra in Non-Hermitian Hamiltonians Having PT Symmetry
- A computable measure of entanglement
- Making Sense of Non-Hermitian Hamiltonians
- Entanglement of a Pair of Quantum Bits
- Non-Hermitian Physics
- On the volume of the set of mixed entangled states
- Nonlinear waves in -symmetric systems
- Entanglement of two qubits mediated by one-dimensional plasmonic waveguides
- Quantum exceptional points of non-Hermitian Hamiltonians and Liouvillians: The effects of quantum jumps
- Observation of parity-time symmetry breaking in a single spin system
- Quantum state tomography across the exceptional point in a single dissipative qubit
- Spectral theory of Liouvillians for dissipative phase transitions
- Observation of coherent perfect absorption at an exceptional point
- Dissipative Phase Transition in Central Spin Systems
- Entangled light from white noise
- Observation of a dissipative phase transition in a one-dimensional circuit QED lattice
- Nonlinear control of PT-symmetry and non-Hermitian topological states
- Algebraic versus exponential decoherence in dissipative many-particle systems
- Probing a dissipative phase transition via dynamical optical hysteresis
- Signatures of a dissipative phase transition in photon correlation measurements
- Entanglement and spin squeezing in non-Hermitian phase transitions
- Quantum jumps in the non-Hermitian dynamics of a superconducting qubit
- Decoherence Induced Exceptional Points in a Dissipative Superconducting Qubit
- Dynamical Control of Quantum Heat Engines Using Exceptional Points
- Non-Hermitian engineering of terahertz light using exceptional points in electrically tuneable collective light-matter interactions
- Steady state entanglement in open and noisy quantum systems at high temperature
- Quantum transport efficiency and Fourier's law
- PT-symmetric quantum Liouvillian dynamics
- PT-symmetry breaking in the steady state of microscopic gain-loss systems
- Observation of Exceptional Points in Thermal Atomic Ensembles
- Topological quantum state control through exceptional-point proximity
- Quantum and semiclassical exceptional points of a linear system of coupled cavities with losses and gain within the Scully-Lamb laser theory
- Signatures of Liouvillian exceptional points in a quantum thermal machine
- Enhancement of quantum heat engine by encircling a Liouvillian exceptional point
- Speeding up entanglement generation by proximity to higher-order exceptional points
- Emergence of PT-symmetry breaking in open quantum systems
- Optimized heat transfer at exceptional points in quantum circuits
- Quantum simulation of parity-time symmetry breaking with a superconducting quantum processor
- Exceptional points for parameter estimation in open quantum systems: Analysis of the Bloch equations
- Strong and weak coupling of two coupled qubits
- -symmetry from Lindblad dynamics in an optomechanical system
- Asymmetric coupling between two quantum emitters
- Steady state entanglement of two coupled qubits
- Generic examples of PT-symmetric qubit (spin 1/2) Liouvillians
- Dynamics of entanglement in a dissipative Bose-Hubbard dimer
- Exceptional points in oligomer chains
- Sudden death of entanglement induced by a minimal thermal environment
- Observing super-quantum correlations across the exceptional point in a single, two-level trapped ion
- Directionality between driven-dissipative resonators
- Resonance fluorescence of two asymmetrically pumped and coupled two-level systems
- Optimal Spin Squeezed Steady State induced by the dynamics of non-hermtian hamiltonians
- Non-reciprocal population dynamics in a quantum trimer