Joint CMSP/QLS Seminar - 15 November

[Quantitative Life Sciences]

JOINT CMSP/QLS GUEST SEMINAR

Thursday, 15 November 2018 14h00
ICTP, Central Area, 2nd floor, old SISSA building, Via Beirut 2

Speaker: Bert Kappen - Donders Institute, Radboud University Nijmegen &  
Gatsby Computational Neuroscience Unit UCL London

Title: The Quantum Boltzmann Machine

We propose to generalise classical maximum likelihood learning to 
density matrices. As the objective function, we propose a quantum 
likelihood that is related to the cross entropy between density 
matrices. We apply this learning criterion to the quantum Boltzmann 
machine (QBM), previously proposed by Amin et al.. We demonstrate for 
the first time learning a quantum Hamiltonian from quantum statistics 
using this approach. For the anti-ferromagnetic Heisenberg and XYZ model 
we recover the true ground state wave function and Hamiltonian. The 
second contribution is to apply quantum learning to learn from classical 
data. Quantum learning uses in addition to the classical statistics also 
quantum statistics for learning. These statistics may violate the Bell 
inequality, as in the quantum case. Maximizing the quantum likelihood 
yields results that are significantly more accurate than the classical 
maximum likelihood approach in several cases. We give an example how the 
QBM can learn a strongly non-linear problem such as the parity problem. 
The solution shows entanglement, quantified by the entanglement entropy.
https://arxiv.org/abs/1803.11278

Indico: http://indico.ictp.it/event/8773/

-- 
Erica Sarnataro
Group Secretary
Quantitative Life Sciences
The Abdus Salam International Centre for Theoretical Physics (ICTP)
Trieste,  Italy
Tel. +39-040-2240623
www.ictp.it/research/qls.aspx
e-mail:qls at ictp.it