Andrea Morello from the Centre for Quantum Computation & Communication Technology in the School of Electrical Engineering & Telecommunications at UNSW will be presenting this webinar
Dial in details are below
Webinar ID 893 3788 7237
Dopant atoms in silicon are a versatile platform for experiments in quantum information processing, as well as quantum foundations. The electron  and nuclear  spin of a 31P donor were the first qubit demonstrated in silicon, and went on to become among of the most coherent qubits in the solid state, with coherence times exceeding 30 seconds , and quantum gate fidelities approaching 99.99% .
In this talk I will present the state of the art and future directions for donor spins in silicon. For quantum information, the current focus is on multi-qubit operations, scale-up and fault tolerance. We have demonstrated an exchange-based 2-qubit CROT gate for electron spins , using a device in which we implanted a high dose of 31P donors. Future experiments will focus on using deterministic, counted single-ion implantation, for which we have recently demonstrated the capability to detect an individual ion with 99.85% confidence . With nuclear spins, we have achieved the landmark result of universal 1- and 2-qubit logic operations with >99% fidelity, and prepared a 3-qubit GHZ entangled state with 92.5% fidelity . We have also demonstrated the coherent electrical control of an electron-nuclear flip-flop qubit , which will greatly facilitate the integration of single-atom qubits in nanoelectronic devices.
Heavier donors possess a high nuclear spin quantum number, which can be used to study quantum chaos in a single quantum system . Chaotic dynamics must be understood and controlled for the correct operation of quantum computers and quantum simulators . In the process of operating a single 123Sb nucleus, we (re)discovered the phenomenon of nuclear electric resonance, and applied it for the first time to a single nuclear spin . This provides yet another pathway to scale up and integrate donor-based quantum technologies.
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