%L discovery1410660
%K Qubits; Quantum information
%J SCIENTIFIC REPORTS
%X 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.
%O © 2013 Macmillan Publishers Limited. This work is licensed under a Creative Commons Attribution 3.0 Unported license.
To view a copy of this license, visit http://creativecommons.org/licenses/by/3.0

PubMed ID: 24177037
%V 3
%A KM Weiss
%A J Miguel-Sanchez
%A JM Elzerman
%T Magnetically tunable singlet-triplet spin qubit in a four-electron InGaAs coupled quantum dot
%D 2013