Opportunities in bosonic quantum simulators subject to particle non-conserving processes

Speaker
Prof. Carlos Navarrete-Benlloch
Affiliation
Shanghai Jiao Tong University
Time
2019-11-29 (Fri) 10:00
Location
上海研究院4号楼329报告厅(理化大楼一楼科技展厅同步视频)
Abstract

Many-body bosonic Hamiltonians are a cornerstone of condensed-matter physics. Quantum simulators, that is, quantum-controlled atomic, optical, or solid-state experimental platforms, holdthe promise to explore such models with a degree of precision and flexibility out of reach for real materials. Common Hamiltonians emerging in condensed-matter preserve the number of particles. In contrast, quantum simulators are intrinsically driven-dissipative systems, where processes that break particle-number conservation can be naturally induced either coherently or incoherently. Here we show that such processes, and down-conversion or pair injection in particular, make the phase diagram of paradigmatic examples such as the extended Bose-Hubbard model much richer.

As side-product, we provide an example of a single-mode Hamiltonian that presents a continuous quantum phase transition, a result that challenges the common intuition that only infinite-size systems present such behavior. We prove that the transition satisfies all the standard requirements, specifically the presence of a sensitive thermodynamic limit and well-defined scaling laws, identifying all critical exponents.

We discuss potential implementations of our ideas in modern quantum-controlled platforms such as trapped atoms and ions, nonlinear optics, superconducting circuits, and mechanical devices.