Speaker
Balazs Dora
Description
Information scrambling and the butterfly effect in chaotic
quantum systems can be diagnosed by out-of-time-ordered
(OTO) commutators through an exponential growth and large
late time value. We show that the latter feature shows up in a
strongly correlated many-body system, a Luttinger liquid,
whose density fluctuations we study at long and short
wavelengths, both in equilibrium and after a quantum
quench. We find rich behaviour combining robustly universal
and non-universal features. The OTO commutators display
temperature and initial state independent behaviour, and
grow as t2 for short times. For the short wavelength density
operator, they reach a sizeable value after the light cone only
in an interacting Luttinger liquid, where the bare excitations
break up into collective modes. We benchmark our findings
numerically on an interacting spinless fermion model in 1D,
and find persistence of central features even in the non-
integrable case. As a non-universal feature, the short time
growth exhibits a distance dependent power.
