Format

Send to

Choose Destination
Phys Rev Lett. 2015 Jan 23;114(3):037401. Epub 2015 Jan 22.

Breaking of valley degeneracy by magnetic field in monolayer MoSe2.

Author information

1
Department of Physics, Cornell University, Ithaca, New York 14853, USA.
2
Department of Physics, Cornell University, Ithaca, New York 14853, USA and Kavli Institute at Cornell, Cornell University, Ithaca, New York 14853, USA.
3
Department of Physics, University of Konstanz, D-78464 Konstanz, Germany.
4
Department of Physics, Lancaster University, Lancaster LA1 4YB, United Kingdom.
5
Kavli Institute at Cornell, Cornell University, Ithaca, New York 14853, USA and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, USA.

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 σ+ and σ- 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.

Supplemental Content

Full text links

Icon for American Physical Society
Loading ...
Support Center