English

Linear Optical Quantum Computing in a Single Spatial Mode

Quantum Physics 2014-11-24 v2

Abstract

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 scheme. Our scheme is suited to 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.

Keywords

Cite

@article{arxiv.1305.3592,
  title  = {Linear Optical Quantum Computing in a Single Spatial Mode},
  author = {Peter C. Humphreys and Benjamin J. Metcalf and Justin B. Spring and Merritt Moore and Xian-Min Jin and Marco Barbieri and W. Steven Kolthammer and Ian A. Walmsley},
  journal= {arXiv preprint arXiv:1305.3592},
  year   = {2014}
}

Comments

5 pages, 4 figures. Updated to be consistent with the published version

R2 v1 2026-06-22T00:17:11.745Z