Spin–layer locking effects in optical orientation of exciton spin in bilayer WSe2

By Aaron M. Jones, Hongyi Yu, J. Ross, P. Klement, N. Ghimire, Jiaqiang Yan, D. Mandrus, W. Yao, Xiaodong Xu. Nature Physics, 2013

319 citations recorded by the source corpus.

Monolayer and few-layer materials present interesting spin and pseudospin states. A study of the coupling between spin, valley and layer degrees of freedom in bilayer WSe2 reveals coherent superpositions of distinct valley configurations and suggests the possibility of electrical control of the spin states. Coupling degrees of freedom of distinct nature plays a critical role in numerous physical phenomena1,2,3,4,5,6,7,8,9,10. The recent emergence of layered materials11,12,13 provides a laboratory for studying the interplay between internal quantum degrees of freedom of electrons14,15. Here we report new coupling phenomena connecting real spin with layer pseudospins in bilayer WSe2. In polarization-resolved photoluminescence measurements, we observe large spin orientation of neutral and charged excitons by both circularly and linearly polarized excitation, with the trion spectrum splitting into a doublet at large vertical electrical field. These observations can be explained as a locking of spin and layer pseudospin in a given valley15, where the doublet implies an electrically induced spin splitting. The observed distinctive behaviour of the trion doublet under polarized excitation further provides spectroscopic evidence of interlayer and intralayer trion species, a promising step towards optical manipulation in van der Waals heterostructures16 through interlayer excitons.

Subfields: Atomic and Molecular Physics, and Optics, Electrical and Electronic Engineering, Materials Chemistry

View Paper: https://www.semanticscholar.org/paper/bd20a63c0b45db89931ac9bec818aa61391704b8

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Atomic and Molecular Physics, and Optics

1. Xiaodong Xu
2. Hongyi Yu
3. W. Yao

In Electrical and Electronic Engineering

1. Hongyi Yu
2. Xiaodong Xu
3. W. Yao
4. X. Cui

In Materials Chemistry

1. Hongyi Yu
2. W. Yao
3. Xiaodong Xu
4. X. Cui
5. K. Mak
6. J. Shan
7. Di Xiao

Citations in the corpus

• Direct observation of spin-polarized bulk bands in an inversion-symmetric semiconductor (2014, background): “Direct observation of spin-polarised bulk bands in an inversion-symmetric semiconductor J. M. Riley,1 F. Mazzola,2 M. Dendzik,3 M. Michiardi,3 T. Takayama,4, 5 L. Bawden,1 C. Granerød,2 M. Leandersson,6 T. Balasubramanian,6 M. Hoesch,7 T. K. Kim,7 H. Takagi,4, 5 W. Meevasana,8, 9 Ph. Hofmann,3 M. S.”
• Valley excitons in two-dimensional semiconductors (2015, background): “In bilayer WSe2, the splitting between the interlayer and interlayer X have been observed in the PL, where the X peak splits into a doublet with the increase of interlayer bias [31].”