Quantum Optics Seminar by Matthew Broome

State of the art in donor based quantum computation 

Substitutional donor atoms in a silicon crystal lattice form the archetypal picture of a solid state quantum computer. Here, the presence of an additional valence electron in the outer atomic orbital is trapped at the donor site and can be used to store and manipulate quantum information in the spin state of the donor system. Experimental works have shown this system to have extremely long relaxation and dephasing coherence times, vital ingredients for the scaling up to a practical quantum computer. At the University of New South Wales we use a unique fabrication strategy based on scanning tunnelling microscopy to fabricated donor based quantum devices with close to atomic precision. In this talk we will cover state of the art in these systems. In particular, I will present our recent results on the measurement of anti-correlated electron spins from exchange coupled phosphorus donors as well their associated singlet-triplet physics.