Year: 2010
Type: article
Abstract: We theoretically demonstrate that nuclear spins can be harnessed to coherently control two-electron spin states in a double quantum dot. Hyperfine interactions lead to an avoided crossing between the spin singlet state and the ${m}_{\text{s}}=+1$ triplet state, ${\text{T}}_{+}$. We show that a coherent superposition of singlet and triplet states can be achieved using finite-time Landau-Zener-St\"uckelberg interferometry. In this system the coherent rotation rate is set by the Zeeman energy, resulting in $\ensuremath{\sim}1\text{ }\text{ns}$ single spin rotations. We analyze the coherence of this spin qubit by considering the coupling to the nuclear spin bath and show that ${T}_{2}^{\ensuremath{\ast}}\ensuremath{\sim}16\text{ }\text{ns}$, in good agreement with experimental data. Our analysis further demonstrates that efficient single qubit and two-qubit control can be achieved using Landau-Zener-St\"uckelberg interferometry.
Source: Physical Review B
Authors: Hugo Ribeiro, J. R. Petta, Guido Burkard
Institutions: University of Konstanz, Princeton University
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2017583703