Quantum Devices Group


Topological qubits

There is a strong current interest in solid-state manifestations of Majorana physics – a Majorana particle being a fermion which is its own antiparticle. Apart from the fundamental aspects of this phenomenon, Majorana qubits have been proposed that are extremely well protected against decoherence due to their topological nature. So far, the study of Majorana fermions has mainly focussed on topological insulators or materials with strong spin-orbit interaction coupled to s-wave superconductors to stabilize the Majorana particles [1]. More recent theories have shown that the requirement for strong intrinsic spin-orbit interaction can be relaxed if this can be engineered using external magnetic fields such as those of magnets of submicron size - opening up the field to a whole new set of material platforms [2,3]. In collaboration with groups at Imperial College London (Dr. Malcolm Connolly and Dr. Will Branford) and the Niels Bohr Institute, Denmark (Prof. Jesper Nygard) we aim to take these novel ideas in to the lab by developing and characterising nanomagnets and coupled them to quasi one-dimensional systems such as carbon nanotubes and InAs/Al heterostructures


[1] Mourik et al, Science 336, 1003 (2012)[2] Kjaergaard et al, Physical Review B 85, 020503 (2012)[3] Klinovaja et al, Physical Review Letters 109, 236801  (2012)