Scrambling and recovery of quantum information in inhomogeneous quenches in two-dimensional conformal field theories
Kanato Goto, Masahiro Nozaki, Shinsei Ryu, Kotaro Tamaoka, Mao Tian Tan
Abstract
We study various quantum quench processes induced by the Möbius/sine-square deformation of the Hamiltonian in two-dimensional conformal field theories starting from the thermofield double state in the two copies of the Hilbert space. These quantum quenches, some of which are directly related to the operator entanglement of the time-evolution operators, allow us to study scrambling and recovery of quantum information. In particular, under the sine-square deformed time evolution, we show from the time dependence of mutual information that the Bell pairs, initially shared by the subsystems of the two Hilbert spaces, may revive even after the mutual information for small subsystems is completely destroyed by quantum information scrambling dynamics. This mutual information is robust against the strong scrambling dynamics. As a consequence, the steady state has a nonlocal correlation shared not by any of two parties but by three parties. In the holographic dual description, a wormhole connecting the two Hilbert spaces may nonlinearly grow with time during the quantum quenches. We also propose effective pictures that describe the dynamics of mutual information during the time evolution by inhomogeneous Hamiltonians. Published by the American Physical Society 2024