Monitored quantum systems and entanglement transitions

Quantum measurements do not only reveal the state of a quantum system; when applied continuously or repeatedly, they can qualitatively change its many-body dynamics, suppressing thermalisation via the quantum Zeno effect. In this talk, I will discuss how the competition between unitary evolution and monitoring gives rise to a new class of nonequilibrium critical phenomena: measurement-induced entanglement transitions, separating phases with extensive (volume-law) and subextensive (area-law) entanglement scaling. Over the past several years, this phenomenon has opened a broad research direction at the interface of quantum statistical mechanics, quantum information, and open quantum systems.

We will see how monitored systems can be understood intuitively through several pictures: entanglement growth, purification dynamics, and mappings to stat-mech models. Building on this, I will discuss results on the effects of interactions, disorder, symmetries, and dimensionality, highlighting how one can alter the measurement-induced critical behavior and the dynamical phases. I will conclude by describing how controlled monitoring can be harnessed for quantum information processing (state preparation, error mitigation), pointing to future applications in quantum computing architectures.

https://us06web.zoom.us/j/86976039901?pwd=Nxw4V42bAvQeF5ao88rbQBLTSHBa5n.1

ID: 869 7603 9901
Passcode: 148188