Selective Probing of Hidden Spin-Polarized States in Inversion-Symmetric Bulk MoS_{2}

Area of Science:

• Condensed matter physics
• Materials science
• Surface science

Background:

• Transition metal dichalcogenides (TMDs) like MoS2 are materials with unique electronic properties.
• Centrosymmetric TMDs, such as bulk MoS2, possess complex electronic structures.
• Understanding spin polarization in these materials is crucial for spintronics applications.

Purpose of the Study:

• To investigate the presence and characteristics of spin polarization in bulk centrosymmetric MoS2.
• To explore the influence of circularly polarized light on spin polarization.
• To demonstrate a method for probing hidden spin-polarized electronic states.

Main Methods:

• Spin- and angle-resolved photoemission spectroscopy (SARPES) was employed.
• Experiments utilized circularly polarized light with varying handedness.
• Theoretical calculations were performed using a three-step photoemission model.

Main Results:

• A significant spin polarization was detected in the bulk of MoS2.
• The direction of spin polarization was reversible by altering the light's circular polarization.
• Calculations confirmed the selective addressing of valley and layer-locked spin-polarized states.

Conclusions:

• SARPES is a powerful technique for observing spin polarization in MoS2.
• Circularly polarized light offers a controllable way to manipulate and probe spin states.
• This work validates theoretical predictions and opens new avenues for exploring spin physics in inversion-symmetric materials.