Quantum Echo in Two-Component Bose-Einstein Condensates

The development of ultracold atom technology has enabled the precise investigations on quantum dynamics of quantum gases. Recently, inspired by experimental advancement, the $SU(1,1)$ echo, akin to the well-known $SU(2)$ spin echo, has been proposed for single-component Bose-Einstein condensate (BEC). In this paper, we investigate the possibility of quantum echo in the more intricate two-component BEC by fully exploiting its underlying symmetry, which is the Lie group $Sp(4,R)$. We demonstrate that quantum echo can occur for the two-component BEC by applying a driving protocol consisting of two steps in each period. The first step can be any Bogoliubov Hamiltonian, while the second step is a Hamiltonian with interactions turned off, which plays a similar role as the $\pi$-pulse in spin echo. We confirm our theoretical results with numerical calculations for different examples of two-component BEC. We further consider the effect of interactions between the excited boson modes on the quantum echo process and discuss the possible experiment implementation of this quantum echo.