Accession Number : ADA550179


Title :   Electron Spin Polarization and Detection in InAs Quantum Dots Through p-Shell Trions


Descriptive Note : Journal article


Corporate Author : NAVAL RESEARCH LAB WASHINGTON DC


Personal Author(s) : Carter, S G ; Badescu, S C ; Bracker, A S


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a550179.pdf


Report Date : 08 Jan 2010


Pagination or Media Count : 7


Abstract : We perform two-color time-resolved spectroscopy of spin dynamics in an ensemble of InAs quantum dots, demonstrating that an electron spin polarization in negatively charged quantum dots can be efficiently generated or detected with pulses tuned to p-shell trions. Due to the polarization selection rules and exchange splitting of the electron spin triplet and singlet trion states, the absorption probability of circularly polarized light depends strongly on the spin state of the resident electron in the quantum dot. This leads to spin selective excitation of electrons to the p-shell trion states, generating a spin polarization in the ensemble of unexcited resident electrons. Manipulating spin states through the excited trion states allows for separation of the excitation wavelength from the emission wavelength for control of the spatial extent of the excited-state wave function.


Descriptors :   *ELECTRONS , *QUANTUM DOTS , EMISSION , ENERGY LEVELS , EXCITATION , INDIUM ARSENIDES , POLARIZATION , QUANTUM THEORY , REPRINTS , SEMICONDUCTORS , SPECTROSCOPY , SPIN STATES , WAVE FUNCTIONS


Subject Categories : Quantum Theory and Relativity


Distribution Statement : APPROVED FOR PUBLIC RELEASE