Robust quantum integrated photonics

by Prof. Haim Suchowski

TAU

at Condensed Matter Seminar

Mon, 05 May 2025, 11:10
Sacta-Rashi Building for Physics (54), room 207

Abstract

Quantum information processing (QIP) relies on high-fidelity quantum state preparation and
accurate unitary operations; this presents a challenge in practical realizations where the
permissible error of quantum operations is smaller than 10 −3 . Integrated photonic circuits are a
leading platform for scalable QIP technologies, yet unavoidable fabrication errors or
inaccuracies in control parameters often limit operational fidelities. This poses a significant
challenge, as even minor systematic errors can degrade fidelity below the fault-tolerant
threshold. A powerful approach for mitigating such errors is the composite pulse method,
originally developed by techniques from nuclear magnetic resonance, where operations are
carefully divided into segments with tailored parameters to enhance robustness. While
traditional composite techniques rely on complex-valued parameter design, integrated
photonics inherently supports only real-valued parameters, making these methods challenging
to implement.
In this talk, I will introduce the detuning-modulated composite segmentation method
developed recently in my labs, enabling robust quantum operations in integrated photonic
platforms without the need for complex phase control. This scheme corrects a wide range of
errors and achieves fidelities exceeding 10 −3 , the fault-tolerant threshold. I will present our
recent numerical and experimental results demonstrating how detuning-modulated composite
segmentation significantly improves error tolerance and enables superior robustness in single-
photon quantum gates, such as high-fidelity Hadamard gates, as well as in two-photon
entangling gates in integrated quantum platforms. Our approach paves the way toward scalable
and fault-tolerant quantum integrated photonic technologies.

Created on 28-04-2025 by Bar Lev, Yevgeny (ybarlev)
Updaded on 28-04-2025 by Bar Lev, Yevgeny (ybarlev)