[Aspuru-Guzik Group List] Visit of Pierre-Luc Dallaire (postdoc candidate)
by Romero Fontalvo, Jhonathan
Hi everyone,
Pierre-Luc is a postdoc candidate for the quantum group. He is finishing
his PhD in the group of Prof. Frank Wilhelm in Saarland University
(Germany). He will be visiting our group for a postdoc interview on *Monday,
June 20th*. Pierre-Luc specializes in condensed matter physics and quantum
simulation. You can find the abstract of his talk below. He will be
presenting a lunch seminar from Noon to 1:30 pm (Pizza and drinks will be
served). I hope you all attend.
For all the people interested in meeting Pierre-Luc, I attach a link to his
calendar so you can select a time spot at your convenience:
Pierre-Luc's schedule
<https://docs.google.com/a/harvard.edu/document/d/1fgqgwdRJr_492l1TjOTqXnofC…>
Cheers,
Jhonathan.
*Title: *Simulating the Fermi-Hubbard model on a quantum computer
*Abstract:* Quantum computers are the ideal platform for quantum
simulations. Given enough coherent operations and qubits, such machines can
be leveraged to simulate strongly correlated materials, where intricate
quantum effects give rise to counter-intuitive macroscopic phenomena such
as high-temperature superconductivity. Many phenomena of strongly
correlated materials are encapsulated in the Fermi-Hubbard model. In
general, no closed form solution is known for lattices of more than one
spatial dimension, but they can be numerically approximated using cluster
methods. To model long-range effects such as order parameters, a powerful
method to compute the cluster's Green's function consists in finding its
self-energy through a variational principle. This allows the possibility of
studying various phase transitions at finite temperature in the
Fermi-Hubbard model. However, a classical cluster solver quickly hits an
exponential wall in the memory (or computation time) required to store the
computation variables. We show theoretically that the cluster solver can be
mapped to a subroutine on a quantum computer whose quantum memory usage
scales linearly with the number of orbitals in the simulated cluster and
the number of measurements scales quadratically. We also provide a gate
decomposition of the cluster Hamiltonian and a simple planar architecture
for a quantum simulator that can also be used to simulate more general
fermionic systems. We briefly analyze the Trotter-Suzuki errors and
estimate the scaling properties of the algorithm for more complex
applications. A quantum computer with a few tens of qubits could therefore
simulate the thermodynamic properties of complex fermionic lattices
inaccessible to classical supercomputers.
--
Jonathan Romero Fontalvo
*Ph.D. Student in Chemical Physics*
*Harvard University*
Website: https://sites.google.com/site/jonathanromeroswebsite/