Home >  Conference > The MPRG

The MPRG

Date : Wednesday, February 15th, 2023 10:30 am - 11:30 am Place : Seminar Room 5 (A615), 6th Floor, ISSP/ Online (Zoom) Lecturer : Dr. Masahiko YAMADA Affiliation : Gakushuin University Committee Chair : Masaki Oshikawa (ex. 63275)
e-mail: oshikawa@issp.u-tokyo.ac.jp
Language in Speech : English

We have proposed a new framework to solve various quantum many-body problems named a matrix product renormalization group (MPRG) [1]. MPRG solves the sign problem of conventional Monte Carlo methods and can be regarded as generalization of a density matrix renormalization group (DMRG) in one dimension. Compared with DMRG, MPRG is directly applicable to infinite systems, higher-dimensional systems, finite-temperature systems, and even to open quantum systems. In particular, a nonvariational variant of MPRG can be used to simulate non-Hermitian models like the Yang-Lee model with a Yang-Lee edge singularity.A variational variant of MPRG has a further application to many Hermitian systems. By utilizing a continuous projected entangled pair state (cPEPS), we can even solve two-dimensional systems at finite temperature. As for the accuracy, cPEPS outperforms PEPS with about a one-digit-higher precision when the same bond dimension is used. The finite-temperature observables like a specific heat are also calculated and compared with a quantum Mote Carlo simulation. Due to the absence of a sign problem, a Trotter error, or a finite-size effect, the observables can easily be extrapolated to the thermodynamic limit only by the bond dimension scaling.

[1] Masahiko G. Yamada et al., arXiv:2212.13267 (2022).

Please access here for the registration in advance.


(Published on: Tuesday January 31st, 2023)