In this work we explore the potential of implementing an optical quantum optimizer using non-linear optics, specifically using sum-frequency generation and/or two photon absorption. This proposal uses Zeno effects to enforce independence constraints and then a linear protocol to find a maximum independent set in a way where the elements of the set can be weighted. Our proposal can either be viewed as an implementation of the entropy computing paradigm presented in [Nguyen et.~al.~Communications Physics 1, 411, 8] which uses real rather than imaginary time evolution, or as quantum annealing within a Zeno constrained subspace. We discuss how such a device could be built, and considerations such as error mitigation, particularly for photon-loss errors. We numerically study aspects of the protocol, including the effect of coherent versus incoherent incarnations of the Zeno effect, finding superior performance from the former.In this work we explore the potential of implementing an optical quantum optimizer using non-linear optics, specifically using sum-frequency generation and/or two photon absorption. This proposal uses Zeno effects to enforce independence constraints and then a linear protocol to find a maximum independent set in a way where the elements of the set can be weighted. Our proposal can either be viewed as an implementation of the entropy computing paradigm presented in [Nguyen et.~al.~Communications Physics 1, 411, 8] which uses real rather than imaginary time evolution, or as quantum annealing within a Zeno constrained subspace. We discuss how such a device could be built, and considerations such as error mitigation, particularly for photon-loss errors. We numerically study aspects of the protocol, including the effect of coherent versus incoherent incarnations of the Zeno effect, finding superior performance from the former.

quant-pharXiv:2604.13032Apr 15, 20260 citations

Photon-loss-tolerant Zeno controlled-SIGN gate

Casey R. Myers, Alexei Gilchrist

We model an optical implementation of a controlled-SIGN gate that makes use of the quantum Zeno effect [Franson et al., Phys. Rev. A 70, 062302 (2004)] in the presence of photon loss. Gate operation is severely affected. However, we show that by using photon loss codes proposed for linear optical quantum computation (LOQC), performance is greatly enhanced, outperforming LOQC equivalents. The technique can be applied to other types of nonlinearities, making the implementation of nonlinear optical gates much more attractive.We model an optical implementation of a controlled-SIGN gate that makes use of the quantum Zeno effect [Franson et al., Phys. Rev. A 70, 062302 (2004)] in the presence of photon loss. Gate operation is severely affected. However, we show that by using photon loss codes proposed for linear optical quantum computation (LOQC), performance is greatly enhanced, outperforming LOQC equivalents. The technique can be applied to other types of nonlinearities, making the implementation of nonlinear optical gates much more attractive.

arXiv:quant-ph/0612176Physical Review AMay 31, 200720 citations

Engineering Photon Sources for Practical Quantum Information Processing

Ben M. Burridge

Oct 1, 20230 citations

Entangling photons via the double quantum Zeno effect

Nicolai ten Brinke, Andreas Osterloh, Ralf Schützhold

We propose a scheme for entangling two photons via the quantum Zeno effect, which describes the inhibition of quantum evolution by frequent measurements and is based on the difference between summing amplitudes and probabilities. For a given error probability ${P}_{\mathrm{error}}$ , our scheme requires that the one-photon loss rate ${\ensuremath{\xi}}_{1\ensuremath{\gamma}}$ and the two-photon absorption rate ${\ensuremath{\xi}}_{2\ensuremath{\gamma}}$ in some medium satisfy ${\ensuremath{\xi}}_{1\ensuremath{\gamma}}/{\ensuremath{\xi}}_{2\ensuremath{\gamma}}=2{P}_{\mathrm{error}}^{2}/{\ensuremath{\pi}}^{2}$, which is significantly improved compared to previous approaches. Again based on the quantum Zeno effect, as well as coherent excitations, we present a possibility to fulfill this requirement in an otherwise linear optics setup.We propose a scheme for entangling two photons via the quantum Zeno effect, which describes the inhibition of quantum evolution by frequent measurements and is based on the difference between summing amplitudes and probabilities. For a given error probability ${P}_{\mathrm{error}}$, our scheme requires that the one-photon loss rate ${\ensuremath{\xi}}_{1\ensuremath{\gamma}}$ and the two-photon absorption rate ${\ensuremath{\xi}}_{2\ensuremath{\gamma}}$ in some medium satisfy ${\ensuremath{\xi}}_{1\ensuremath{\gamma}}/{\ensuremath{\xi}}_{2\ensuremath{\gamma}}=2{P}_{\mathrm{error}}^{2}/{\ensuremath{\pi}}^{2}$, which is significantly improved compared to previous approaches. Again based on the quantum Zeno effect, as well as coherent excitations, we present a possibility to fulfill this requirement in an otherwise linear optics setup.

arXiv:1103.2938Physical Review AAug 10, 20115 citations

{P}_{\mathrm{error}}

, our scheme requires that the one-photon loss rate ${\ensuremath{\xi}}_{1\ensuremath{\gamma}}$ and the two-photon absorption rate ${\ensuremath{\xi}}_{2\ensuremath{\gamma}}$ in some medium satisfy ${\ensuremath{\xi}}_{1\ensuremath{\gamma}}/{\ensuremath{\xi}}_{2\ensuremath{\gamma}}=2{P}_{\mathrm{error}}^{2}/{\ensuremath{\pi}}^{2}$, which is significantly improved compared to previous approaches. Again based on the quantum Zeno effect, as well as coherent excitations, we present a possibility to fulfill this requirement in an otherwise linear optics setup.