290S/290K Quantum Materials Seminar: Sam Garratt (UCB); Wednesday, January 24 at 2:00 PM Pacific Time in 402 Physics South
Time/Venue Wednesday, January 24 at 2:00 PM Pacific Time in 402 Physics South and via Zoom:
https://berkeley.zoom.us/j/99523499113pwd=REovb3pyam03WXQwbEhrU3dqNHZvdz09
Meeting ID: 995 2349 9113 Passcode: 600704
Host Ehud Altman
Title Proxy eigenstates from quantum search
Abstract In generic many-body quantum systems, and at finite energy densities, it is not possible to efficiently resolve individual eigenstates. Even with a fault-tolerant quantum computer, the time required grows exponentially with the number of degrees of freedom. I will introduce a quantum algorithm that creates quantum states with narrow energy width. In time scaling polynomially with the number of degrees of freedom, this algorithm allows us to achieve inverse polynomial energy width, and with inverse polynomial error. I will then show how our algorithm can be used as the basis for an efficient test of the eigenstate thermalization hypothesis (ETH) in large systems. Interestingly, if our system is described by the ETH, the states we create act as indirect probes of the eigenstates themselves.