Adaptive Phase Measurements in Linear Optical Quantum Computation

Abstract

Photon counting induces an effective nonlinear optical phase shift on certain states derived by linear optics from single photons. Although this no nlinearity is nondeterministic, it is sufficient in principle to allow scalable linear optics quantum computation (LOQC). The most obvious way to encode a qubit optically is as a superposition of the vacuum and a single photon in one mode -- so-called "single-rail" logic. Until now this approach was thought to be prohibitively expensive (in resources) compared to "dual-rail" logic where a qubit is stored by a photon across two modes. Here we attack this problem with real-time feedback control, which can realize a quantum-limited phase measurement on a single mode, as has been recently demonstrated experimentally. We show that with this added measurement resource, the resource requirements for single-rail LOQC are not substantially different from those of dual-rail LOQC. In particular, with adaptive phase measurements an arbitrary qubit state $\alpha |0⟩+\beta |1⟩$ can be prepared deterministically.

References in corpus (13)

• Quantum computation with optical coherent states
• Optical quantum computation using cluster states
• Experimental Controlled-NOT Logic Gate for Single Photons in the Coincidence Basis
• Adaptive homodyne measurement of optical phase
• Realization of a photonic CNOT gate sufficient for quantum computation
• Quantum-optical catalysis: generating "Schroedinger kittens" by means of linear optics
• Remote preparation of a single-mode photonic qubit by measuring field quadrature noise
• Experimental demonstration of a non-destructive controlled-NOT quantum gate for two independent photon-qubits
• High-fidelity quantum logic operations using linear optical elements
• Adaptive single-shot phase measurements: The full quantum theory
• Non-deterministic Gates for Photonic Single Rail Quantum Logic
• Utilizing Encoding in Scalable Linear Optics Quantum Computing
• Comparison of LOQC C-sign gates with ancilla inefficiency and an improvement to functionality under these conditions

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