Phonon influence on the measurement of spin states in double quantum dots using the quantum point contact
arXiv:1303.6657 · doi:10.1103/PhysRevB.88.125303
Abstract
We study the influence of phonon scattering on the single-triplet measurement of two-electron spin states in a double quantum dot doped with two electrons. We point out that at low temperatures phonon-induced relaxation to the ground state suppresses transitions to doubly occupied singlet states which are the source of detectable current fluctuations in this measurement scheme. Thus, for a relatively strong electron-phonon interaction present in the system, the two configurations display the same noise characteristics. In this way, coupling to phonons reduces the distinguishability between the singlet and triplet configurations. Under such conditions, the measurement scheme is no longer valid even though the temporal characteristics of the measurement process and measurement- induced localization are essentially unchanged.
10 pages
References in corpus (15)
- Single-shot read-out of an individual electron spin in a quantum dot
- Coherent control of a single electron spin with electric fields
- Demonstration of Entanglement of Electrostatically Coupled Singlet-Triplet Qubits
- Fast Single-Charge Sensing with an rf Quantum Point Contact
- Singlet-triplet decoherence due to nuclear spins in a double quantum dot
- Counting statistics of transport through Coulomb blockade nanostructures: High-order cumulants and non-Markovian effects
- Suppression of spin relaxation in an InAs nanowire double quantum dot
- Singlet-triplet splitting in double quantum dots due to spin orbit and hyperfine interactions
- Non-destructive measurement of electron spins in a quantum dot
- Phonon-induced decoherence for a quantum dot spin qubit operated by Raman passage
- Phonon-assisted tunneling between singlet states in two-electron quantum dot molecules
- Measuring current by counting electrons in a nanowire quantum dot
- Strong quantum memory at resonant Fermi edges revealed by shot noise
- Coupling symmetry of quantum dot states
- Parity measurement of one- and two-electron double well systems