Spin Superfluidity in the ν=0 Quantum Hall State of Graphene.
Strong electron interactions can lead to a variety of broken-symmetry phases in monolayer graphene. In the quantum Hall regime, the interaction effect are enhanced by the formation of highly degenerate Landau levels, catalyzing the emergence of such phases. Recent magnetotransport studies show evidence that the ν=0 quantum Hall state of graphene is in an insulating canted antiferromagnetic phase with the Néel vector lying within the graphene plane. Here, we show that this Néel order can be detected via two-terminal spin transport. We find that a dynamic and inhomogeneous texture of the Néel vector can mediate nearly dissipationless (superfluid) transport of spin angular momentum polarized along the z axis, which could serve as a strong support for the antiferromagnetic scenario. The injection and detection of spin current in the ν=0 region can be achieved using the two spin-polarized edge channels of the |ν|=2 quantum Hall state. Measurements of the dependence of the spin current on the length of the ν=0 region would provide direct evidence for spin superfluidity.
Department of Physics, Queens College of the City University of New York, Queens, New York 11367, USA.|Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA.
So
S
Takei
Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.
Amir
A
Yacoby
Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.
Bertrand I
BI
Halperin
Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA.
Yaroslav
Y
Tserkovnyak