TY - JOUR
T1 - Control of spin diffusion and suppression of the Hanle oscillation by the coexistence of spin and valley Hall effects in Dirac materials
AU - Zhang, Xian Peng
AU - Huang, Chunli
AU - Cazalilla, Miguel A.
N1 - Publisher Copyright:
© 2019 American Physical Society.
PY - 2019/6/5
Y1 - 2019/6/5
N2 - In addition to spin, electrons in many Dirac materials possess an additional pseudospin degree of freedom known as "valley." In materials where the spin and valley degrees of freedom are weakly coupled, they can be both excited and controlled independently. In this work, we study a model describing the interplay of the spin and valley Hall effects in such two-dimensional materials. We demonstrate the emergence of an additional longitudinal neutral current that is both spin and valley polarized. The additional neutral current allows to control the spin density by tuning the magnitude of the valley Hall effect. In addition, the interplay of the two effects can suppress the Hanle oscillation, that is, the oscillation of the nonlocal resistance of a Hall bar device with in-plane magnetic field. The latter observation provides a possible explanation for the absence of the Hanle oscillation in a number of recent experiments. Our work also opens the possibility to engineer the conversion between the valley and spin degrees of freedom in two-dimensional materials.
AB - In addition to spin, electrons in many Dirac materials possess an additional pseudospin degree of freedom known as "valley." In materials where the spin and valley degrees of freedom are weakly coupled, they can be both excited and controlled independently. In this work, we study a model describing the interplay of the spin and valley Hall effects in such two-dimensional materials. We demonstrate the emergence of an additional longitudinal neutral current that is both spin and valley polarized. The additional neutral current allows to control the spin density by tuning the magnitude of the valley Hall effect. In addition, the interplay of the two effects can suppress the Hanle oscillation, that is, the oscillation of the nonlocal resistance of a Hall bar device with in-plane magnetic field. The latter observation provides a possible explanation for the absence of the Hanle oscillation in a number of recent experiments. Our work also opens the possibility to engineer the conversion between the valley and spin degrees of freedom in two-dimensional materials.
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U2 - 10.1103/PhysRevB.99.245106
DO - 10.1103/PhysRevB.99.245106
M3 - Article
AN - SCOPUS:85069711514
SN - 2469-9950
VL - 99
JO - Physical Review B
JF - Physical Review B
IS - 24
M1 - 245106
ER -