Special 290S/290K Quantum Materials Seminar speaker Nikita Astrakhantsev (Uni Zürich) Monday, November 14 at 11 am in Physics South 325

Time/Venue Monday, November 14 at 11 am in Physics South 325
 and via Zoom:
https://berkeley.zoom.us/j/99523499113pwd=REovb3pyam03WXQwbEhrU3dqNHZvdz09
Meeting ID: 995 2349 9113 Passcode: 600704
Host Joel Moore
Title Spin-liquid states on the pyrochlore lattice and Rydberg atoms
simulator
Abstract The XXZ model on the three-dimensional frustrated pyrochlore
lattice describes a family of rare-earth materials showing signatures of
fractionalization and no sign of ordering in the neutron-scattering
experiments. The phase diagram of such XXZ model is believed to host
several spin-liquid states with fascinating properties, such as emergent
U(1) electrodynamics with emergent photon and possible
confinement-deconfinement transition. Unfortunately, numerical studies
of such lattice are hindered by three-dimensional geometry and absence
of obvious small parameters.
In this talk, I will present my work [Phys. Rev. X 11, 041021] on the
variational study of the pyrochlore XXZ model using the RVB-inspired and
Neural-Network-inspired ansätze. They yield energies better than known
results of DMRG at finite bond dimension. With these wave functions, we
study the properties of frustrated phase at the Heisenberg point, and
observe signatures of long-range dimer correlations.
Lastly, I will sketch the prospects of using the Programmable Rydberg
Simulator platform for the study of these spin-liquid states. I will
construct two possible embeddings of the pyrochlore XXZ model onto the
Rydberg atoms simulator, employing the notion of spin ice and
perturbative hexagon flip processes.