Theorie Kolloquium | May 03, 16:30
Randomness, Entanglement, and Thermal Equilibrium in the Quantum World
How does thermodynamic equilibrium emerge from the reversible, coherent dynamics of quantum many-body systems? This question underpins statistical mechanics, and has been a subject of intense theoretical study for decades. Today, programmable quantum simulators and computers offer new ways to address this question experimentally, prompting the development of novel theoretical frameworks. In this Colloquium I will give an overview of two recent developments in this direction. The first is 'deep thermalization', which describes the emergence of maximally-random wavefunction distributions on a subsystem from projectively measuring the rest of the system--a stronger condition than conventional thermalization, with the potential for useful applications in quantum computing. The second, termed 'pseudothermalization', builds on recent ideas from quantum cryptography. It describes a class of non-thermal states that have very limited quantum entanglement, but are indistinguishable from highly-entangled thermal states to any observer with limited resources. These results highlight the subtle roles of randomness, entanglement, and the observer's resources in characterizing thermal equilibrium in programmable quantum matter.
University of Texas at Austin
Seminar Room 0.03, ETP
Contact: Xhek Turkeshi