Magnetically tunable singlet-triplet spin qubit in a four-electron InGaAs coupled quantum dot
Elzerman, Jeroen M.
- Journal Article
Rights / licenseCreative Commons Attribution 3.0 Unported
A pair of self-assembled InGaAs quantum dots filled with two electrons can act as a singlet-triplet spin qubit that is robust against nuclear spin fluctuations as well as charge noise. This results in a T2* coherence time two orders of magnitude longer than that of a single electron, provided the qubit is operated at a particular “sweet spot” in gate voltage. However, at this fixed operating point the ground-state splitting can no longer be tuned into resonance with e.g. another qubit, limiting the options for coupling multiple qubits. Here, we propose using a four-electron coupled quantum dot to implement a singlet-triplet qubit that features a magnetically tunable level splitting. As a first step towards full experimental realization of this qubit design, we use optical spectroscopy to demonstrate the tunability of the four-electron singlet-triplet splitting in a moderate magnetic field. Show more
Journal / seriesScientific Reports
Pages / Article No.
PublisherNature Publishing Group
SubjectQubits; Quantum information
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