Scrambling in random unitary circuits: exact results
We study the scrambling of quantum information in local random unitary circuits by focusing on the tripartite information proposed by Hosur et al. We provide exact results for the averaged Rényi-2 tripartite information in two cases: (i) the local gates are Haar random and (ii) the local gates are dual-unitary and randomly sampled from a single-site Haar-invariant measure. We show that the latter case defines a one-parameter family of circuits, and prove that for a “maximally chaotic” subset of this family quantum information is scrambled faster than in the Haar-random case. Our approach is based on a standard mapping onto an averaged folded tensor network, that can be studied by means of appropriate recurrence relations. By means of the same method, we also revisit the computation of out-of-time-ordered correlation functions, rederiving known formulas for Haar-random unitary circuits, and presenting an exact result for maximally chaotic random dual-unitary gates.
2020
2020-12-21 12:19:36
1033
nonequilibrium statistical mechanics, quantum chaos
neravnovesna statistična mehanika, kvantni kaos
Bruno
Bertini
70
Lorenzo
Piroli
70
UDK
4
536.93
ISSN pri članku
9
2469-9950
DOI
15
10.1103/PhysRevB.102.064305
COBISS_ID
3
43003139
OceCobissID
13
2997348
RAZ_Bertini_Bruno_2020.pdf
1065637
Predstavitvena datoteka
2020-12-21 12:21:29
0
Izvorni URL
2021-02-05 12:28:32