第1回　物理工学科教室談話会（講師：Inti Sodemann）

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概要：The picture of fractional quantum Hall states as liquids of composite particles made from electrons bound to fluxes has evolved over the years as a central paradigm in the understanding of these phases. A recent proposal on the compressible phase that arises in half-filled Landau levels allows to consistently incorporate the particle-hole symmetry by viewing the composite fermion as a Dirac particle. In turn, the natural habitat for this Dirac composite fermion is the surface of a chiral topological insulator protected by an anti-unitary particle-hole symmetry with a single Dirac cone. In this talk I will describe generalizations of these ideas to the case of N-component landau levels, such as those arising in quantum Hall bilayers (N=2) and graphene (N=4). When multi-component Landau levels are half filled they can be viewed as the surface of a chiral topological insulator with N Dirac cones. I will describe gapped phases that respect the particle-hole symmetry and are top
ologically ordered and discuss their potential experimental realization.
紹介教員：渡辺悠樹講師、求幸年教授