2025/05/02 by Sengoku, Shunsuke, Po, Hoi Chun, Watanabe, Haruki · 1 citation
#FOS: Physical sciences #Other Condensed Matter (cond-mat.other) #Quantum Physics (quant-ph) #Statistical Mechanics (cond-mat.stat-mech) #Strongly Correlated Electrons (cond-mat.str-el)
paper · doi:10.48550/arxiv.2505.01010
Recent studies have revealed that frustration-free models, expressed as sums of finite-range interactions or hoppings, exhibit several properties markedly different from those of frustrated models. In this work, we demonstrate that, by relaxing the finite-range condition to allow for exponentially decaying hoppings, one can build gapped frustration-free systems that realize Chern insulators as well as quasi-degenerate ground states with finite-size splittings. Moreover, by permitting power-law decaying hoppings, we also construct a gapless band metal whose finite-size gap scales inversely with the system size L. These findings serve as an important step toward clarifying the general properties of frustration-free systems and those represented by tensor network states.