arXiv subjects

O. V. Borzenkova

Publications and source records attributed to O. V. Borzenkova.

4 recordsLinked to original sources

arXiv2025

Optimization of the time-multiplexed SPDC source at 900-950 nm range

In the field of quantum technology, single photons have emerged as a pivotal resource, prompting the development of heralded single photon sources (HSPS) with enhanced generation probability. The majority of such sources are based on spontaneous parametric down-conversion (SPDC), but they exhibit a low single photon generation probability. The multiplexing principle (arXiv:quant-ph/0205103) has been proposed as a solution to this problem. This paper presents a demonstration of a time-multiplexed HSPS based on the SPDC process, including accurate calculations and modeling of key source characteristics, specifically purity and heralding efficiency. Furthermore, the paper provides an analysis and approximation of the probability of a single photon post-application of time multiplexing.

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arXiv2024

Error mitigated variational algorithm on a photonic processor

Our study demonstrates successful error mitigation of indistinguishability-related noise in a quantum photonic processor through the application of the zero-noise extrapolation technique. By measuring observable values at different error levels, we were able to extrapolate towards a noise-free regime. We examined the impact of partial distinguishability of photons in a two-qubit processor implementing the variational quantum eigensolver for a Schwinger Hamiltonian. Our findings highlight the effectiveness of the extrapolation technique in mitigating indistinguishability-related noise and improving the accuracy of Hamiltonian eigenvalue estimation.

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arXiv2022

Two-qubit quantum photonic processor manufactured by femtosecond laser writing

We present an experimental implementation of a two-qubit photonic quantum processor fabricated using femtosecond laser writing technology. We employ femtosecond laser writing to create a low-loss reconfigurable photonic chip implementing precise single-qubit and two-qubit operations. The performance of single-qubit and two-qubit gates is characterized by full process tomography. An exemplary application of the processor to determining the ground state energy of an H2 molecule using the variational quantum eigensolver algorithm is demonstrated. Our results highlight the potential of femtosecond laser writing technology to deliver high quality small-scale quantum photonic processors.

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arXiv2021

Variational Simulation of Schwinger's Hamiltonian with Polarisation Qubits

The numerical emulation of quantum physics and quantum chemistry often involves an intractable number of degrees of freedom and admits no known approximation in general form. In practice, representing quantum-mechanical states using available numerical methods becomes exponentially more challenging with increasing system size. Recently quantum algorithms implemented as variational models, have been proposed to accelerate such simulations. Here we study the effect of noise on the quantum phase transition in the Schwinger model, within a variational framework. The experiments are built using a free space optical scheme to realize a pair of polarization qubits and enable any two-qubit state to be experimentally prepared up to machine tolerance. We specifically exploit the possibility to engineer noise and decoherence for polarization qubits to explore the limits of variational algorithms for NISQ architectures in identifying and quantifying quantum phase transitions with noisy qubits. We find that despite the presence of noise one can detect the phase transition of the Schwinger Hamiltonian even for a two-qubit system using variational quantum algorithms.

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