CMSA Quantum Matter in Mathematics and Physics: Maximal quantum chaos of the critical Fermi surface
SEMINARS, CMSA EVENTS
Speaker:
Maria Tikhanovskaya - Harvard
In this talk, I will describe many-body quantum chaos in a recently proposed large-N theory for critical Fermi surfaces in two spatial dimensions, by computing out-of-time-order correlation functions. I will use the ladder identity proposed by Gu and Kitaev, and show that the chaos Lyapunov exponent in this system takes on the maximum possible value of 2πkBT/ℏ, where T is the absolute temperature. In addition, by varying the dynamic critical exponent, I will show that the maximal chaos persists only in the regime where quasiparticles are absent. When quasiparticles are present, the Lyapunov exponent scales with the temperature as ~ T^a, where a < 1, which is parametrically smaller than the maximal rate.
https://harvard.zoom.us/j/
Password: cmsa