ELFT HÍRADÓ

[Andras Palyi <palyi AT mail.bme.hu>]

Dear Colleagues, 
 
Next Monday the BME Exotic Quantum Phases seminar series continues with 
Attila Szabo's talk.
 
Speaker: Attila Szabo (Cambridge)
Title: "Neural network wave functions and the sign problem"
Time: Oct 19 Monday, 14:15
Location: online in Teams
 
Abstract: "Neural quantum states (NQS) are a promising approach to study 
many-body quantum physics. However, they face a major challenge when applied 
to lattice models: Convolutional networks struggle to converge to ground 
states with a nontrivial sign structure. We tackle this problem by proposing 
a neural network architecture with a simple, explicit, and interpretable 
phase ansatz, which can robustly represent such states and achieve 
state-of-the-art variational energies for both conventional and frustrated 
antiferromagnets. In the latter case, our approach uncovers low-energy states 
that exhibit the Marshall sign rule and are therefore inconsistent with the 
expected ground state. Such states are the likely cause of the obstruction 
for NQS-based variational Monte Carlo to access the true ground states of 
these systems. We discuss the implications of this observation and suggest 
potential strategies to overcome the problem. 
(https://arxiv.org/abs/2002.04613 <https://arxiv.org/abs/2002.04613>)"
 
About the speaker: Attila is a young Hungarian theoretical physicist who 
studied physics in Cambridge, is just finishing his PhD under the supervision 
of Claudio Castelnovo there, and will start his first postdoc in Oxford soon.
 
Link to join the Teams meeting:
https://teams.microsoft.com/l/meetup-join/19%3ab2147125eff74ee9b0bb7e857d428727%40thread.tacv2/1602748273263?context=%7b%22Tid%22%3a%226a3548ab-7570-4271-91a8-58da00697029%22%2c%22Oid%22%3a%22f8b27e90-dbca-4bb5-813c-d6415577ec35%22%7d
 
<https://teams.microsoft.com/l/meetup-join/19%3ab2147125eff74ee9b0bb7e857d428727%40thread.tacv2/1602748273263?context=%7b%22Tid%22%3a%226a3548ab-7570-4271-91a8-58da00697029%22%2c%22Oid%22%3a%22f8b27e90-dbca-4bb5-813c-d6415577ec35%22%7d>

Best regards,
Andras Palyi