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Register a new userConvolutional restricted Boltzmann machine aided Monte Carlo: An application to Ising and Kitaev models
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Daniel Alcalde Puente
Publication date
2020
fields
Physics
and research's language is
English
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Machine learning is becoming widely used in analyzing the thermodynamics of many-body condensed matter systems. Restricted Boltzmann Machine (RBM) aided Monte Carlo simulations have sparked interest recently, as they manage to speed up classical Monte Carlo simulations. Here we employ the Convolutional Restricted Boltzmann Machine (CRBM) method and show that its use helps to reduce the number of parameters to be learned drastically by taking advantage of translation invariance. Furthermore, we show that it is possible to train the CRBM at smaller lattice sizes, and apply it to larger lattice sizes. To demonstrate the efficiency of CRBM we apply it to the paradigmatic Ising and Kitaev models in two-dimensions.
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We present a worm-type Monte Carlo study of several typical models in the three-dimensional (3D) U(1) universality class, which include the classical 3D XY model in the directed flow representation and its Villain version, as well as the 2D quantum Bose-Hubbard (BH) model with unitary filling in the imaginary-time world-line representation. From the topology of the configurations on a torus, we sample the superfluid stiffness $rho_s$ and the dimensionless wrapping probability $R$. From the finite-size scaling analyses of $rho_s$ and of $R$, we determine the critical points as $T_c ({rm XY}) =2.201, 844 ,1(5)$ and $T_c ({rm Villain})=0.333, 067, 04(7)$ and $(t/U)_c ({rm BH})=0.059 , 729 ,1(8)$, where $T$ is the temperature for the classical models, and $t$ and $U$ are respectively the hopping and on-site interaction strength for the BH model. The precision of our estimates improves significantly over that of the existing results. Moreover, it is observed that at criticality, the derivative of a wrapping probability with respect to $T$ suffers from negligible leading corrections and enables a precise determination of the correlation length critical exponent as $ u=0.671 , 83(18)$. In addition, the critical exponent $eta$ is estimated as $eta=0.038 , 53(48)$ by analyzing a susceptibility-like quantity. We believe that these numerical results would provide a solid reference in the study of classical and quantum phase transitions in the 3D U(1) universality, including the recent development of the conformal bootstrap method.
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