Tricritical Kibble-Zurek Scaling in Rydberg Atom Ladders

Abstract: The Kibble-Zurek (KZ) mechanism is being actively explored on quantum simulation platforms. In this work, we study the KZ scaling around tricritical phase transition points, with Rydberg atom ladders as a concrete incarnation. The criticality is of Ising and Potts type for two- and three-leg ladders, respectively. When slowly ramping across or near the tricritical point from the disordered phase to the ordered phase, we obtain universal power-law scaling in agreement with conventional KZ predictions. We study a "tangential" KZ ramping that both begins and ends in the disordered phase, a novel protocol enabled by the two-dimensional phase diagram. The tangential KZ directly reveals subleading critical exponents of the critical point. Finally, we explore the regime of intermediate-speed ramping and find a dynamical analog of the celebrated Zamolodchikov's c-theorem. Practically, our work provides an immediately relevant protocol for current experiments to pinpoint the elusive tricritical points. More broadly, tangential and intermediate-speed rampings go beyond the conventional KZ paradigm and introduce new insights into critical quantum dynamics.