Emerging Non-Hermitian Topology in a Chiral-Driven-Dissipative Bose-Hubbard Model

Area of Science:

• Quantum optics
• Condensed matter physics
• Non-Hermitian physics

Background:

• Driven-dissipative systems are crucial for quantum technologies.
• Bose-Hubbard models describe interacting bosons in lattices.
• Non-Hermiticity breaks fundamental symmetries, leading to unique phenomena.

Purpose of the Study:

• To introduce and investigate a driven-dissipative Bose-Hubbard chain with broken time-reversal symmetry.
• To explore the emergence of non-Hermitian topological phases in an interacting photonic system.
• To demonstrate the potential implementation of such systems using superconducting circuits.

Main Methods:

• Utilizing a Gaussian variational ansatz for theoretical analysis.
• Numerical investigation of the driven-dissipative Bose-Hubbard model.
• Analysis of the nonequilibrium phase diagram and topological properties.

Main Results:

• Stabilization of the steady-state solution by an inhomogeneous driving amplitude.
• Observation of a nonequilibrium phase diagram with low- and high-density phases.
• Identification of topological amplification and a finite non-Hermitian winding number in the phase coexistence region.

Conclusions:

• The study reveals the emergence of non-Hermitian topological phases in an interacting driven-dissipative system.
• Topological amplification is a key phenomenon in the coexistence region.
• The proposed model offers a pathway for experimental realization with superconducting circuits.