Control of valley polarization in monolayer MoS2 by optical helicity.

@article{Mak2012ControlOV,
  title={Control of valley polarization in monolayer MoS2 by optical helicity.},
  author={Kin Fai Mak and Keliang He and Jie Shan and Tony F. Heinz},
  journal={Nature nanotechnology},
  year={2012},
  volume={7 8},
  pages={
          494-8
        }
}
  • K. Mak, K. He, +1 author T. Heinz
  • Published 2012
  • Materials Science, Physics, Medicine
  • Nature nanotechnology
Electronic and spintronic devices rely on the fact that free charge carriers in solids carry electric charge and spin. There are, however, other properties of charge carriers that might be exploited in new families of devices. In particular, if there are two or more minima in the conduction band (or maxima in the valence band) in momentum space, and if it is possible to confine charge carriers in one of these valleys, then it should be possible to make a valleytronic device. Valley polarization… Expand
Valley polarization in MoS2 monolayers by optical pumping.
TLDR
It is demonstrated that optical pumping with circularly polarized light can achieve a valley polarization of 30% in pristine monolayer MoS(2), demonstrating the viability of optical valley control and valley-based electronic and optoelectronic applications in MoS (2) monolayers. Expand
Valley Polarization by Spin Injection in a Light-Emitting van der Waals Heterojunction
TLDR
This demonstration of spin injection and magnetoelectronic control over valley polarization provides a new opportunity for realizing combined spin and valleytronic devices based on spin-valley locking in semiconducting TMDCs. Expand
Optical generation of valley polarization in atomically thin semiconductors
Electronic valleys refer to energy extrema in momentum space. In the same way as spin is utilized for spintronics, valleys can be considered as pseudo-spins for valley based electronics andExpand
Valley-polarized exciton currents in a van der Waals heterostructure
TLDR
The generation and transport over mesoscopic distances of valley-polarized excitons in a device based on a type-II TMDC heterostructure is shown and electrostatic traps are used to increase the exciton concentration by an order of magnitude, opening the route to achieving a coherent quantum state of valley, polarizedexcitons via Bose–Einstein condensation. Expand
Generation and detection of pure valley current by electrically induced Berry curvature in bilayer graphene
Bilayer graphene can host topological currents that are robust against defects and are associated with the electron valleys. It is now shown that electric fields can tune this topological valleyExpand
Valley-polarized exciton dynamics in a 2D semiconductor heterostructure
TLDR
This work created interlayer exciton spin-valley polarization by means of circularly polarized optical pumping and determined a valley lifetime of 40 nanoseconds, which enables the visualization of the expansion of a valley-polarized exciton cloud over several micrometers. Expand
Electrical control of the valley Hall effect in bilayer MoS2 transistors.
TLDR
It is shown that the valley Hall effect in bilayer MoS2 transistors can be controlled with a gate voltage, which is consistent with symmetry-dependent Berry curvature and valley Hall conductivity in bilayers MoS 2. Expand
Valley polarization in stacked MoS2 induced by circularly polarized light
Manipulation of valley pseudospins is crucial for future valleytronics. The emerging transition metal dichalcogenides (TMDs) provide new possibilities for exploring the interplay among the quantumExpand
Optical initialization of a single spin-valley in charged WSe2 quantum dots
TLDR
This work provides unambiguous evidence for localized holes with a net spin in optically active WSe2 quantum dots and initialize their spin-valley state with the helicity of the excitation laser under small magnetic fields, estimating a lower bound of the valley lifetime of a single charge in a quantum dot from the recombination time to be of the order of nanoseconds. Expand
Electrical generation and control of the valley carriers in a monolayer transition metal dichalcogenide.
TLDR
Direct electrical generation and control of valley carriers opens up new dimensions in utilizing both the spin and valley DOFs for next-generation electronics and computing. Expand
...
1
2
3
4
5
...

References

SHOWING 1-10 OF 44 REFERENCES
Valley polarization in MoS2 monolayers by optical pumping.
TLDR
It is demonstrated that optical pumping with circularly polarized light can achieve a valley polarization of 30% in pristine monolayer MoS(2), demonstrating the viability of optical valley control and valley-based electronic and optoelectronic applications in MoS (2) monolayers. Expand
MoS_2 as an ideal material for valleytronics: valley-selective circular dichroism and valley Hall effect
A two-dimensional honeycomb lattice harbors a pair of inequivalent valleys in the k-space electronic structure, in the vicinities of the vertices of a hexagonal Brillouin zone, K±. It is particularlyExpand
Coupled spin and valley physics in monolayers of MoS2 and other group-VI dichalcogenides.
We show that inversion symmetry breaking together with spin-orbit coupling leads to coupled spin and valley physics in monolayers of MoS2 and other group-VI dichalcogenides, making possible controlsExpand
Valley-selective circular dichroism of monolayer molybdenum disulphide
TLDR
It is shown, using first principles calculations, that monolayer molybdenum disulphide is an ideal material for valleytronics, for which valley polarization is achievable via valley-selective circular dichroism arising from its unique symmetry. Expand
Valley-contrasting physics in graphene: magnetic moment and topological transport.
TLDR
The pseudospin associated with the valley index of carriers has an intrinsic magnetic moment, in close analogy with the Bohr magneton for the electron spin, forming the basis for the valley-based electronics applications. Expand
Detection of valley polarization in graphene by a superconducting contact.
TLDR
This work shows how Andreev reflection can be used to detect the valley polarization of edge states produced by a magnetic field, in the absence of intervalley relaxation. Expand
Valley filter and valley valve in graphene
The potential of graphene for carbon electronics rests on the possibilities offered by its unusual band structure to create devices that have no analogue in silicon-based electronics1,2. ConductionExpand
Valley-dependent optoelectronics from inversion symmetry breaking
Inversion symmetry breaking allows contrasted circular dichroism in different $k$-space regions, which takes the extreme form of optical selection rules for interband transitions at high symmetryExpand
Electronic properties of MoS2 nanoparticles
We present a first principle, theoretical study of MoS2 nanoparticles that provides a unified explanation of measured photoluminescence spectra and recent STM measurements as a function of size. InExpand
Spintronics: Fundamentals and applications
Spintronics, or spin electronics, involves the study of active control and manipulation of spin degrees of freedom in solid-state systems. This article reviews the current status of this subject,Expand
...
1
2
3
4
5
...