Linear optical quantum computing in a single spatial mode.

Journal article

We present a scheme for linear optical quantum computing using time-bin-encoded qubits in a single spatial mode. We show methods for single-qubit operations and heralded controlled-phase (cphase) gates, providing a sufficient set of operations for universal quantum computing with the Knill-Laflamme-Milburn [Nature (London) 409, 46 (2001)] scheme. Our protocol is suited to currently available photonic devices and ideally allows arbitrary numbers of qubits to be encoded in the same spatial mode, demonstrating the potential for time-frequency modes to dramatically increase the quantum information capacity of fixed spatial resources. As a test of our scheme, we demonstrate the first entirely single spatial mode implementation of a two-qubit quantum gate and show its operation with an average fidelity of 0.84±0.07.

Authors: Humphreys, P; Metcalf, B; Spring, J; Moore, M; Jin, X

• Publication status: Published
• Journal: Physical Review Letters
• Volume: 111
• Issue: 15
• Pages: 150501
• Publication date: 2013-10-01
• DOI: 10.1103/physrevlett.111.150501
• EISSN: 1079-7114
• ISSN: 0031-9007
• Language: English
• Keywords: quant-ph