Program

LSU SQuInT Event Map

SESSION 12: Quantum information meets many-body physics (Theatre)

Chair: (Nicolas Menicucci (Royal Melbourne Inst. Tech.))
1:30pm - 2:15pmXie Chen, IQIM, Caltech
Coupled layer construction of three dimensional topological codes with 'Fractons'

Abstract. Three dimensional quantum codes can exhibit exotic topological properties compared to their two dimensional counterparts. In two dimensions, topological excitations are point like and can move freely in space, inducing nontrivial braiding statistics as they wind around each other. In three dimensions, topological excitations can also be point like. But it has been discovered that sometimes their motion are highly restricted, such that they can only move in a sub-dimensional manifold or their motion are correlated with each other. Such point excitations are dubbed 'fractons' and in this talk we try to address the question of where they come from. We show that one class of 'fractons' can emerge by coupling layers of two dimensional topological codes and inducing a condensation of 'particles loops'. By making connections between the 'fracton' topological order and the more conventional two dimensional ones, we are able to generalize 'fractons' models beyond the stabilizer framework.

2:15pm - 2:45pmAdrian Chapman, CQuIC, New Mexico
Classical simulation of quantum circuits by dynamical localization: analytic results for Pauli-observable propagation in time-dependent disorder

Abstract. Matchgate circuits have been extensively studied due to (i) their classical simulability properties and (ii) their close connection to the physics of noninteracting fermions in one dimension. We extend (i) by introducing a classically efficient algorithm for the Lieb-Robinson commutator norm of a local observable under Heisenberg evolution by a nearest-neighbor matchgate circuit. This is surprising in light of the fact that the Heisenberg evolution itself cannot even be stored efficiently by a classical computer in general. We apply our result by (ii) to the study of fermions propagating through a one-dimensional lattice in the presence of spatio-temporally fluctuating disorder and demonstrate a method to classify this propagation into either the localized, diffusive, or ballistic dynamical phase. We find that our results coincide with known classifications of Anderson localization in the statically disordered case, but the localized phase can also be seen to survive in the presence of weakly fluctuating disorder. We expect our results to inspire the application of localization as a classical simulation technique for more general classes of quantum circuits.

SQuInT Chief Organizer
Akimasa Miyake, Assistant Professor
amiyake@unm.edu

SQuInT Co-Organizer
Mark M. Wilde, Assistant Professor LSU
mwilde@phys.lsu.edu

SQuInT Administrator
Gloria Cordova
gjcordo1@unm.edu
505 277-1850

SQuInT Event Coordinator
Karen Jones, LSU
kjones@cct.lsu.edu

SQuInT Founder
Ivan Deutsch, Regents' Professor
ideutsch@unm.edu

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