Diego Porras, Consejo Superior de Investigaciones Científicas (CSIC)

Leuchs-Russell-Auditorium, A.1.500, Staudtstr. 2

Location details

Abstract:
Directional amplification in non-reciprocal driven-dissipative systems is an exciting phenomenon with applications in areas like qubit read-out and quantum sensing. Directional amplification can be described within a topological framework analogous to topological insulator band theory. The key idea is the description of the system's linear response in terms of the singular value decomposition of the non-Hermitian dynamical matrix. Directional amplification is governed by topologically protected zero-singular values which dominate the system's linear response. I will show how topological amplification can be applied to design broadband directional amplifiers of microwave radiation for superconducting quantum computers. I will also present recent results on how to extend those ideas to interacting systems [Rassaert et al, arXiv:2411.08965], in particular to the study of chiral Bose-Hubbard driven-dissipative chains. We have addressed this many-body system using a variational Gaussian ansatz and found a non-equilibrium phase diagram with a topological amplification phase.