Ionization

Physics

Atom (system on chip)

Atomic physics

Computer science

Rydberg atom

Quantum mechanics

Chain (unit)

Embedded system

Rydberg formula

Quantum

Physical Review Letters

A recent experiment in the Rydberg atom chain observed unusual oscillatory quench dynamics with a charge density wave initial state, and theoretical works identified a set of many-body ``scar states'' showing nonthermal behavior in the Hamiltonian as potentially responsible for the atypical dynamics. In the same nonintegrable Hamiltonian, we discover several eigenstates at an infinite temperature that can be represented exactly as matrix product states with a finite bond dimension, for both periodic boundary conditions (two exact $E=0$ states) and open boundary conditions (two $E=0$ states and one each $E=\ifmmode\pm\else\textpm\fi{}\sqrt{2}$). This discovery explicitly demonstrates the violation of the strong eigenstate thermalization hypothesis in this model and uncovers exact quantum many-body scar states. These states show signatures of translational symmetry breaking with a period-2 bond-centered pattern, despite being in one dimension at an infinite temperature. We show that the nearby many-body scar st...

Exact Quantum Many-Body Scar States in the Rydberg-Blockaded Atom Chain