



01653nas a2200169   4500008004100000245007700041210006900118260001500187300001100202490000700213520111300220100002301333700001701356700002501373700001601398856006901414       2018                        eng d00aAbsence of Thermalization in Finite Isolated Interacting Floquet Systems0 aAbsence of Thermalization in Finite Isolated Interacting Floquet  c2018/01/29  a0143110 v973 a<p>Conventional wisdom suggests that the long time behavior of isolated interacting periodically driven (Floquet) systems is a featureless maximal entropy state characterized by an infinite temperature. Efforts to thwart this uninteresting fixed point include adding sufficient disorder to realize a Floquet many-body localized phase or working in a narrow region of drive frequencies to achieve glassy non-thermal behavior at long time. Here we show that in clean systems the Floquet eigenstates can exhibit non-thermal behavior due to finite system size. We consider a one-dimensional system of spinless fermions with nearest-neighbor interactions where the interaction term is driven. Interestingly, even with no static component of the interaction, the quasienergy spectrum contains gaps and a significant fraction of the Floquet eigenstates, at all quasienergies, have non-thermal average doublon densities. We show that this non-thermal behavior arises due to emergent integrability at large interaction strength and discuss how the integrability breaks down with power-law behavior in system size.</p>1 aSeetharam, Karthik1 aTitum, Paraj1 aKolodrubetz, Michael1 aRefael, Gil  uhttps://journals.aps.org/prb/abstract/10.1103/PhysRevB.97.014311