Spins, phonons and photons in silicon
Juha Muhonen
Donor spins in silicon are a promising candidate for quantum information platform, combining good quantum properties (coherence times, gate fidelities) with the strong industrial know-how of semiconductor fabrication. Their application potential is, however, currently constrained by the lack of convenient coupling and readout methods for the spins. To address these constraints, our group develops new methods for both the readout and coupling of the spins. Specifically, we concentrate on linking them to other quantum systems such as mechanical resonators and optical light that can then be used as readout and coupling avenues.
Here, I will discuss our recent efforts and results in i) hybrid electro-optical readout of the donors and ii) coupling the donors to an optomechanical “transducer”.
The electro-optical readout is based on a bound exciton transition and will allow higher operational temperatures than current readout methods and simplify the scaling up requirements considerably. Notably, our readout will be based on commercial quantum dot detectors from Semiqon Oy.
The optomechanical bridge will allow interaction between the donor spin qubits and telecom-wavelength photons. We couple the spins (via either strain or magnetic field gradient) to the mechanical motion of a nanoresonator, whose motion in turn influences the resonance frequency of an optical cavity. This allows reading out the spin state with a telecom wavelength laser and the mechanical system can be used to couple spins.
