Breaking of valley degeneracy by magnetic field in monolayer MoSe2

MacNeill, David and Heikes, Colin and Mak, Kin Fai and Anderson, Zachary and Kormanyos, Andor and Zolyomi, Viktor and Park, Jiwoong and Ralph, Daniel C. (2015) Breaking of valley degeneracy by magnetic field in monolayer MoSe2. Physical review letters, 114 (3). ISSN 0031-9007

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Abstract

Using polarization-resolved photoluminescence spectroscopy, we investigate the breaking of valley degeneracy by an out-of-plane magnetic field in back-gated monolayer MoSe2 devices. We observe a linear splitting of -0.22 meV/T between luminescence peak energies in sigma(+) and sigma(-) emission for both neutral and charged excitons. The optical selection rules of monolayer MoSe2 couple the photon handedness to the exciton valley degree of freedom; so this splitting demonstrates valley degeneracy breaking. In addition, we find that the luminescence handedness can be controlled with a magnetic field to a degree that depends on the back-gate voltage. An applied magnetic field, therefore, provides effective strategies for control over the valley degree of freedom.

Item Type:
Journal Article
Journal or Publication Title:
Physical review letters
Additional Information:
© 2015 American Physical Society
Uncontrolled Keywords:
/dk/atira/pure/subjectarea/asjc/3100
Subjects:
ID Code:
73356
Deposited By:
Deposited On:
09 Apr 2015 08:46
Refereed?:
Yes
Published?:
Published
Last Modified:
26 Sep 2020 03:14