Phys.org October 26, 2018
An international team of researchers (USA – Princeton University, Germany) proposes a quadrupolar exchange-only spin qubit that is highly robust against charge noise and nuclear spin dephasing, the dominant decoherence mechanisms in quantum dots. The qubit consists of four electrons trapped in three quantum dots and operates in a decoherence-free subspace to mitigate dephasing due to nuclear spins. Because of on-site exchange mediated by the Coulomb interaction, the qubit energy splitting is electrically controllable and can amount to several GHz even in the “off” configuration, making it compatible with conventional microwave cavities. The new method makes it possible to use spins as memory for quantum computers… read more. TECHNICAL ARTICLE
Schematic representation of the new spin qubit consisting of four electrons (red) with their spins (blue) in their semiconductor environment (grey). Credit: Maximilian Russ/Guido Burkard