Majorana fermions are spatially localized superpositions of electron and hole excitations in the middle of a superconducting energy gap. These unusual particles have been predicted to occur at the interface between a magnetic and superconducting electrode, in contact with a topological insulator. A single qubit can be encoded nonlocally in a pair of spatially separated Majorana fermions. Such Majorana qubits are in demand as building blocks of a topological quantum computer, but direct experimental tests of the nonlocality remain elusive. We will discuss methods to detect Majorana fermions by shot noise and discuss how the familiar flux qubit might be used to read out the state of a Majorana qubit.
Instituut Lorentz, Universiteit Leiden