title: Quantum interference between three two-spin states in a double quantum dot.
abstract: Qubits based on the singlet (S) and the triplet (T(0), T(+)) states in double quantum dots have been demonstrated in separate experiments. It has been recently proposed theoretically that under certain conditions a quantum interference could occur from the interplay between these two qubit species. Here we report experiments and modeling that confirm these theoretical predictions and identify the conditions under which this interference occurs. Density matrix calculations show that the interference pattern manifests primarily via the occupation of the common singlet state. The S/T(0) qubit is found to have a much longer coherence time as compared to the S/T(+) qubit.
authors.affiliation: Institute for Microstructural Sciences, National Research Council Canada, Ottawa, Ontario Canada K1A 0R6.
authors.forename: S A
authors.initials: SA
authors.lastname: Studenikin
authors.forename: G C
authors.initials: GC
authors.lastname: Aers
authors.forename: G
authors.initials: G
authors.lastname: Granger
authors.forename: L
authors.initials: L
authors.lastname: Gaudreau
authors.forename: A
authors.initials: A
authors.lastname: Kam
authors.forename: P
authors.initials: P
authors.lastname: Zawadzki
authors.forename: Z R
authors.initials: ZR
authors.lastname: Wasilewski
authors.forename: A S
authors.initials: AS
authors.lastname: Sachrajda