title: Spin of semiconductor quantum dots under hydrostatic pressure.
abstract: 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.
authors.affiliation: Department of Physics and Center for Nanophysics and Advanced Materials, University of Maryland, College Park, MD 20742, USA.
authors.forename: Yun
authors.initials: Y
authors.lastname: Tang
authors.forename: Alexander F
authors.initials: AF
authors.lastname: Goncharov
authors.forename: Viktor V
authors.initials: VV
authors.lastname: Struzhkin
authors.forename: Russell J
authors.initials: RJ
authors.lastname: Hemley
authors.forename: Min
authors.initials: M
authors.lastname: Ouyang