Generic Two-Qubit Photonic Gates Implemented by Number-Resolving Photodetection

Abstract

We combine numerical optimization techniques [Uskov et al., Phys. Rev. A 79, 042326 (2009)] with symmetries of the Weyl chamber to obtain optimal implementations of generic linear-optical KLM-type two-qubit entangling gates. We find that while any two-qubit controlled-U gate, including CNOT and CS, can be implemented using only two ancilla resources with success probability S > 0.05, a generic SU(4) operation requires three unentangled ancilla photons, with success S > 0.0063. Specifically, we obtain a maximal success probability close to 0.0072 for the B gate. We show that single-shot implementation of a generic SU(4) gate offers more than an order of magnitude increase in the success probability and two-fold reduction in overhead ancilla resources compared to standard triple-CNOT and double-B gate decompositions.

5 pages, 3 figures

References in corpus (7)

• The Quantum Internet
• Efficient Toffoli Gates Using Qudits
• Efficient routing of single photons by one atom and a microtoroidal cavity
• Methods for linear optical quantum Fredkin gate
• Maximal Success Probabilities of Linear-Optical Quantum Gates
• General linear-optical quantum state generation scheme: Applications to maximally path-entangled states
• Linear-Optical Hyperentanglement-Assisted Quantum Error-Correcting Code

Cited by in corpus (5)

• Non-linear Boson Sampling
• Imperfect Linear Optical Photonic Gates with Number-Resolving Photodetection
• Optimal entangling operations between deterministic blocks of qubits encoded into single photons
• Optimal Encoding Capacity of a Linear Optical Quantum Channel
• Proposed Experiment in Two-Qubit Linear Optical Photonic Gates for Maximal Success Rates