Degree
Doctor of Philosophy (PhD)
Department
Physics and Astronomy
Document Type
Dissertation
Abstract
Modeling many-body quantum systems is widely regarded as one of the most promising applications for near-term noisy quantum computers. However, in the near term, system size limitation will remain a severe barrier for applications in materials science or strongly correlated systems. A promising avenue of research is to combine many-body physics with machine learning for the classification of distinct phases. I present a workflow that synergizes quantum computing, many-body theory, and quantum machine learning (QML) for studying strongly correlated systems. In particular, it can capture a putative quantum phase transition of the stereotypical strongly correlated system, the Hubbard model. Following the recent proposal of the hybrid classical-quantum algorithm for the two-site dynamical mean-field theory (DMFT), I present a modification that allows the self-consistent solution of the single bath site DMFT. The modified algorithm can be generalized for multiple bath sites. This approach is used to generate a database of zero-temperature wavefunctions of the Hubbard model within the DMFT approximation. I then use a QML algorithm to distinguish between the metallic phase and the Mott insulator phase to capture the metal-to-Mott insulator phase transition. I train a recently proposed quantum convolutional neural network(QCNN) and then utilize the QCNN as a quantum classifier to capture the phase transition region. This work provides a recipe for application to other phase transitions in strongly correlated systems and represents an exciting application of small-scale quantum devices realizable with near-term technology.
Date
7-24-2024
Recommended Citation
Baul, Anshumitra, "QUANTUM CLASSICAL ALGORITHM FOR SOLVING THE HUBBARD MODEL VIA DYNAMICAL MEAN-FIELD THEORY" (2024). LSU Doctoral Dissertations. 6555.
https://repository.lsu.edu/gradschool_dissertations/6555
Committee Chair
Moreno, Juana.