Seminário de Computação e Informação Quântica 

25/03/2015, 10:00 — 11:00 — Sala P3.10, Pavilhão de Matemática
Abolfazl Bayat, University College London

Universal single-frequency oscillation of the entanglement spectrum after a local quench

Long-lived single-frequency oscillations in the local non-equilibrium dynamics of a quantum many-body system is an exceptional phenomenon. In fact, till now, it has never been observed, nor predicted, for the physically relevant case where a system is prepared to be quenched from one quantum phase to another. Here we show how the quench dynamics of the entanglement spectrum may reveal the emergence of such oscillations in a correlated quantum system with Kondo impurities. The oscillations we find are characterized by a single frequency which is proportional to the Kondo temperature of the system. The frequency is universal, being independent of the amount of energy released by the local quench, and scales as $1/N$ for $N$ being the size of the system. Importantly, the universal frequency manifests itself also in local observables, such as the spin-spin correlation function of the impurities.