Quantum spin ice under a [111] magnetic field: from pyrochlore to kagome

          @misc{ scivideos_PIRSA:17060040,
            doi = {10.48660/17060040},
            url = {https://pirsa.org/17060040},
            author = {Onoda, Shigeki},
            keywords = {Quantum Matter},
            language = {en},
            title = {Quantum spin ice under a [111] magnetic field:  from pyrochlore to kagome},
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2017},
            month = {jun},
            note = {PIRSA:17060040 see, \url{https://scivideos.org/index.php/pirsa/17060040}}
          }
          

Abstract

Quantum spin ice, modeled for magnetic rare-earth pyrochlores, has attracted great interest for hosting a U(1) quantum spin liquid, which involves spin-ice monopoles as gapped deconfined spinons, as well as gapless excitations analogous to photons. However, the global phase diagram under a [111] magnetic field remains open. Here we uncover by means of unbiased quantum Monte-Carlo simulations that a supersolid of monopoles, showing both a superfluidity and a partial ionization, intervenes the kagome spin ice and a fully polarized ionic monopole insulator, in contrast to classical spin ice where a direct discontinuous phase transition takes place. We also show that on cooling, kagome spin ice evolves towards a valence bond solid. Possible relevance to experiments is discussed.