Spin of semiconductor quantum dots under hydrostatic pressure.
Spin coherence dynamics of semiconductor quantum dots under hydrostatic pressure has been investigated by combining the ultrafast optical orientation method with the diamond-anvil cell technique. Spin confined within quantum dots is observed to be robust up to several gigapascals, while electron and exciton Landé g factors show novel bistable characteristics prior to the first-order structural transition. This observation is attributed to the existence of a theoretically predicted metastable intermediate state at the nanoscale, for which there has been no previous experimental support. The results also reveal pressure enhanced fundamental exchange interactions for large-sized quantum dots with sizable anisotropy. These findings shed insight into underlying mechanisms of long-debated nanoscale solid-state transformations in semiconductors and are also crucial for the development of future quantum information processing and manipulation based on spin qubits of quantum dots.
Tang
Yun
Y
Department of Physics and Center for Nanophysics and Advanced Materials, University of Maryland, College Park, MD 20742, USA.
Goncharov
Alexander F
AF
Struzhkin
Viktor V
VV
Hemley
Russell J
RJ
Ouyang
Min
M