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Abstract: We have studied the ground state and thermodynamic properties of the anisotropic 3-state Potts model on square lattice by means of the tensor network-based numerical method. The phase diagrams of this model in the ground state and at finite temperature are identified. The singular behavior at the critical endpoint along the phase boundary is carefully investigated. It is discovered that the sharp peaks appear in the second-order derivative of the field as well as the first-order derivative of the magnetization with respect to temperature on the phase boundary. Our numerical results confirm the prediction of Fisher et al. about the critical endpoint. [Copyright &y& Elsevier]

Graphical abstract The phase diagram in plane of temperature and magnetic field for the spin-1/2 kagome Heisenberg antiferromagnet is theoretically obtained for the first time. It is comprised of five phases: the gapless quantum spin liquid (QSL) phase, the algebraic paramagnetic liquid (APL) phase that possesses both paramagnetic properties and algebraic behaviors inherited from the QSL, the field-induced ordered phase, the intermediate (spin canted) phase, and the conventional paramagnetic state. Abstract Quantum fluctuations from frustration can trigger quantum spin liquids (QSLs) at zero temperature. However, it is unclear how thermal fluctuations affect a QSL. We employ state-of-the-art tensor network-based methods to explore the ground state and thermodynamic properties of the spin- 1 / 2 kagomé Heisenberg antiferromagnet (KHA). Its ground state is shown to be consistent with a gapless QSL by observing the absence of zero-magnetization plateau as well as the algebraic behaviors of susceptibility and specific heat at low temperatures, respectively. We show that there exists an algebraic paramagnetic liquid (APL) that possesses both the paramagnetic properties and the algebraic behaviors inherited from the QSL. The APL is induced under the interplay between quantum fluctuations from geometrical frustration and thermal fluctuations. By studying the temperature-dependent behaviors of specific heat and magnetic susceptibility, a finite-temperature phase diagram in a magnetic field is suggested, where various phases are identified. This present study gains useful insight into the thermodynamic properties of the spin-1/2 KHA with or without a magnetic field and is helpful for relevant experimental studies. [ABSTRACT FROM AUTHOR]

Abstract: By the infinite time-evolving block decimation (iTEBD) technique, the magnetization process in spin-1 Ising model with single-ion anisotropy under external field is investigated in the thermodynamic limit. An updated phase diagram is proposed, and the detailed magnetic structures of the phase diagram are uncovered. It must be noted that two interesting phases with same magnetization plateau (M z =0) but different magnetic structures are distinguished. Furthermore, they are verified to be an ideal Néel phase and an ideal large-D phase respectively. In addition, a first-order quantum phase transition line between them is determined to be at D=1. [Copyright &y& Elsevier]