title: Tunable spin loading and T1 of a silicon spin qubit measured by single-shot readout.
abstract: We demonstrate single-shot readout of a silicon quantum dot spin qubit, and we measure the spin relaxation time T1. We show that the rate of spin loading can be tuned by an order of magnitude by changing the amplitude of a pulsed-gate voltage, and the fraction of spin-up electrons loaded can also be controlled. This tunability arises because electron spins can be loaded through an orbital excited state. Using a theory that includes excited states of the dot and energy-dependent tunneling, we find that a global fit to the loading rate and spin-up fraction is in good agreement with the data.
authors.affiliation: Department of Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
authors.forename: C B
authors.initials: CB
authors.lastname: Simmons
authors.forename: J R
authors.initials: JR
authors.lastname: Prance
authors.forename: B J
authors.initials: BJ
authors.lastname: Van Bael
authors.forename: Teck Seng
authors.initials: TS
authors.lastname: Koh
authors.forename: Zhan
authors.initials: Z
authors.lastname: Shi
authors.forename: D E
authors.initials: DE
authors.lastname: Savage
authors.forename: M G
authors.initials: MG
authors.lastname: Lagally
authors.forename: R
authors.initials: R
authors.lastname: Joynt
authors.forename: Mark
authors.initials: M
authors.lastname: Friesen
authors.forename: S N
authors.initials: SN
authors.lastname: Coppersmith
authors.forename: M A
authors.initials: MA
authors.lastname: Eriksson