Spin and pseudospins in 2D semiconductors
Xiaodong Xu
Department of Physics and MSE
University of Washington
Electronic valleys are extrema of Bloch energy bands in momentum
space. Having multiple valleys gives the electron states pseudospin
degrees of freedom in addition to their real spin. In this talk, I
will discuss our experimental progress on the investigation of spins
and pseudospins using atomically thin semiconductors, which are either
single or bilayer group VI transition metal dichalcogenides. These new
2D semiconductors behave as remarkable excitonic systems, providing an
exciting laboratory for optical, electrical and magnetic control of
the valley degrees of freedom. I will also discuss strong coupling
effects between spin, valley, and layer pseudo-spins in bilayers,
which lead to spin polarization in electronic bands in the presence of
bulk inversion symmetry and allow electrical control of spin states. I
will conclude the talk with the discussion of spatially indirect
exciton properties in monolayer semiconducting heterostructures and
single quantum emitters in monolayers.