Qdev Seminar: Krysta Svore

Quantum Computing with Probabilistic Circuits

In order to realize a quantum algorithm on a quantum computer, we require methods to efficiently decompose a quantum algorithm into a hardware-dependent, fault-tolerant quantum circuit.  I will begin by describing the phases of a compiler for a quantum computer.  An essential compilation phase is the synthesis of single-qubit quantum circuits.  I will then describe the challenges in single-qubit circuit synthesis and show how the use of measurement allows one to synthesize circuits that have an expected number of T gates of about 1/3 of what is required by optimal, deterministic, ancilla-free decompositions over the Clifford+T gate set. Such improvements are crucial since T gates are roughly 100 times more costly than a Clifford or Pauli gate.  Finally, I will present our probabilistic quantum circuit synthesis protocol and describe its role in a compiler for quantum computers, highlighting the cost benefits it provides.
 
Joint work with Alex Bocharov and Martin Roetteler.
http://arxiv.org/abs/1409.3552 , http://arxiv.org/abs/1404.5320 , http://arxiv.org/abs/1311.1074