Non-Hermitian topological quantum states in a reservoir-engineered transmon chain

Abstract

Dissipation in open systems enriches the possible symmetries of the Hamiltonians beyond the Hermitian framework allowing the possibility of novel non-Hermitian topological phases, which exhibit long-living end states that are protected against disorder. So far, non-Hermitian topology has been explored only in settings where probing genuine quantum effects has been challenging. We theoretically show that a non-Hermitian topological quantum phase can be realized in a reservoir-engineered transmon chain. The spatial modulation of dissipation is obtained by coupling each transmon to a quantum circuit refrigerator allowing in-situ tuning of dissipation strength in a wide range. By solving the many-body Lindblad master equation using a combination of the density matrix renormalization group and third quantization approaches, we show that the topological end modes and the associated phase transition are visible in simple reflection measurements with experimentally realistic parameters. Finally, we demonstrate that genuine quantum effects are observable in this system via robust and slowly decaying long-range quantum entanglement of the topological end modes, which can be generated passively starting from a locally excited transmon.

17 pages, 6 figures

References in corpus (16)

• Supplementary information for "Quantum supremacy using a programmable superconducting processor"
• Charge insensitive qubit design derived from the Cooper pair box
• Scalable multi-particle entanglement of trapped ions
• Realizing Repeated Quantum Error Correction in a Distance-Three Surface Code
• Selective enhancement of topologically induced interface states in a dielectric resonator chain
• Periodic Table for Topological Bands with Non-Hermitian Bernard-LeClair Symmetries
• Observation of Non-Hermitian Skin Effect and Topology in Ultracold Atoms
• Realization of an Error-Correcting Surface Code with Superconducting Qubits
• Detecting topological invariants in nonunitary discrete-time quantum walks
• Two-Qubit State Tomography using a Joint Dispersive Read-Out
• Noise-resilient Edge Modes on a Chain of Superconducting Qubits
• Exceptional odd-frequency pairing in non-Hermitian superconducting systems
• Non-Hermitian many-body topological excitations in interacting quantum dots
• X-shaped and Y-shaped Andreev resonance profiles in a superconducting quantum dot
• Recent Developments in Quantum-Circuit Refrigeration
• Collective bosonic effects in an array of transmon devices

Cited by in corpus (2)

• Transfer learning from Hermitian to non-Hermitian quantum many-body physics
• Non-hermitian topology and entanglement in an optomechanical superlattice