Quantum Engineering of Superconducting Array Detectors In Low-Light Applications

Introduction

Optical measurements are fundamental to experimental science and observations of nature. At the single photon level, superconducting nanowire single-photon detectors (SNSPDs) are well-established as the gold standard in measurement, due to their near-unit efficiency, negligible noise, and ultrafast response.

Impact on Various Fields

Building SNSPD arrays and simultaneously extracting intensity, spectral, and spatial resolution from a device at the single photon level will revolutionize:

• Astronomical measurements
• Spectrometry in chemistry and life sciences
• Quantum imaging

Key to unlocking this potential is to marry concepts from detector tomography with robust high-yield detector fabrication, the integration of complementary optical technologies, and low heat-load scalable readout schemes.

Project Overview

QuESADILLA tackles these challenges head-on, with a series of experiments demonstrating the groundbreaking potential of quantum detector engineering. In contrast to engineering quantum states of light for metrology, QuESADILLA will shift that paradigm by engineering the quantum mechanical response of the detector itself.

Concepts Introduced

QuESADILLA introduces the concepts of:

1. Modal decomposition of the positive operator valued measure (POVM)
2. Quantum-enhanced POVM engineering in low-light applications

To do so, arrays of SNSPDs in combination with lithographically-written etalons and dielectric coatings will be developed, in concert with state-of-the-art scalable approaches to large scale quantum tomography.

Achievements and Goals

QuESADILLA will exceed the state of the art in many areas:

• Performing the first modal decomposition of detector tomography
• Achieving the largest tomographic reconstruction of a quantum detector
• Demonstrating quantum detector engineering using nonclassical ancilla states
• Showcasing etalon array reconstructive spectrometry with single photons
• Exploiting the fastest electronic shutter speed of any optical sensor to enable the highest dynamic range detection of continuous illumination