Quantum state tomography across the exceptional point in a single dissipative qubit

Abstract

Open systems with gain and loss, described by non-trace-preserving, non-Hermitian Hamiltonians, have been a subject of intense research recently. The effect of exceptional-point degeneracies on the dynamics of classical systems has been observed through remarkable phenomena such as the parity-time symmetry breaking transition, asymmetric mode switching, and optimal energy transfer. On the other hand, consequences of an exceptional point for quantum evolution and decoherence are hitherto unexplored. Here, we use post-selection on a three-level superconducting transmon circuit with tunable Rabi drive, dissipation, and detuning to carry out quantum state tomography of a single dissipative qubit in the vicinity of its exceptional point. Quantum state tomography reveals the PT symmetry breaking transition at zero detuning, decoherence enhancement at finite detuning, and a quantum signature of the exceptional point in the qubit relaxation state. Our observations demonstrate rich phenomena associated with non-Hermitian physics such as non-orthogonality of eigenstates in a fully quantum regime and open routes to explore and harness exceptional point degeneracies for enhanced sensing and quantum information processing.

10 pages, 8 figures

References in corpus (22)

• Real Spectra in Non-Hermitian Hamiltonians Having PT Symmetry
• Charge insensitive qubit design derived from the Cooper pair box
• Photonic Floquet Topological Insulators
• Nonreciprocal light transmission in parity-time-symmetric whispering-gallery microcavities
• The physics of exceptional points
• Dynamically encircling exceptional points in a waveguide: asymmetric mode switching from the breakdown of adiabaticity
• Observation of high coherence in Josephson junction qubits measured in a three-dimensional circuit QED architecture
• Loss-induced suppression and revival of lasing
• Topological energy transfer in an optomechanical system with exceptional points
• Pseudo-Hermitian Representation of Quantum Mechanics
• Spawning rings of exceptional points out of Dirac cones
• Probing topological invariants in the bulk of a non-Hermitian optical system
• Amplification and squeezing of quantum noise with a tunable Josephson metamaterial
• Observation of non-Hermitian degeneracies in a chaotic exciton-polariton billiard
• Approaching Unit Visibility for Control of a Superconducting Qubit with Dispersive Readout
• Observation of parity-time symmetry breaking transitions in a dissipative Floquet system of ultracold atoms
• Observation of parity-time symmetry breaking in a single spin system
• Observation of the exceptional point in cavity magnon-polaritons
• Non-Hermitian Quantum Sensing: Fundamental Limits and Non-Reciprocal Approaches
• Observation of PT phase transition in a simple mechanical system
• Dispersive magnetometry with a quantum limited SQUID parametric amplifier
• Sensitivity of parameter estimation near the exceptional point of a non-Hermitian system

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