Journal club presentation:
"Experimental superposition of orders of quantum gates" by Procopio et. al.
(Nature Comms 6, 7913 (2015)
Arash Ahmadi, Institute for Quantum Computing
Quantum computers achieve a speed-up by placing quantum bits (qubits) in superpositions of different states. However, it has recently been appreciated that quantum mechanics also allows one to ‘superimpose different operations’. Furthermore, it has been shown that using a qubit to coherently control the gate order allows one to accomplish a task—determining if two gates commute or anti-commute—with fewer gate uses than any known quantum algorithm. Here we experimentally demonstrate this advantage, in a photonic context, using a second qubit to control the order in which two gates are applied to a first qubit. We create the required superposition of gate orders by using additional degrees of freedom of the photons encoding our qubits. The new resource we exploit can be interpreted as a superposition of causal orders, and could allow quantum algorithms to be implemented with an efficiency unlikely to be achieved on a fixed-gate-order quantum computer.
If you are coming from the Lazaridis Centre, take the 11:35am shuttle to RAC 1 and return on the 1:15pm shuttle. A light lunch will be served.
475 Wes Graham Way
Waterloo, ON N2L 6R2