arXiv subjects

Niels Noordzij

Publications and source records attributed to Niels Noordzij.

4 recordsLinked to original sources

arXiv2025

Controlling the recovery time of the superconducting nanowire single-photon detector with a voltage-controlled cryogenic tunable resistor

Superconducting nanowire single-photon detectors (SNSPD), owing to their unique performance, are currently the standard detector in most demanding single-photon experiments. One important metric for any single-photon detector is the deadtime (or recovery time), defined as the minimum temporal separation between consecutive detection events. In SNSPDs, the recovery time is more subtle, as the detection efficiency does not abruptly drop to zero when the temporal separation between detection events gets smaller, instead, it increases gradually as the SNSPD current recovers. SNSPD's recovery time is dominated by its kinetic inductance, the readout impedance, and the degree of saturation of internal efficiency. Decreasing the kinetic inductance or increasing the readout impedance can accelerate the recovery process. Significant reduction of the SNSPD recovery time, by, for example, adding a series resistor in the readout circuitry, is possible but can lead to detector latching which hinders further detector operation or enforces underbiasing and hence a reduction in detection efficiency. Previous research has demonstrated passive resistive networks for the reduction of recovery time that rely on trial and error to find the appropriate resistance values. Here we show, using a novel, cryogenically compatible, and tunable resistor technology, one can find the optimized impedance values, delivering fast SNSPD recovery time, while maintaining maximum internal detection efficiency. Here we show an increase of more than 2 folds in both maximum achievable detection rates and the achievable detection efficiency at high photon fluxes, demonstrating detection rates as high as 120 Mcps with no loss of internal detection efficiency.

physics.ins-det↗

arXiv2024

Attojoule superconducting thermal logic and memories

Due to stringent thermal budgets in cryogenic technologies such as superconducting quantum computers and sensors, minimizing the energy dissipation and power consumption of cryogenic electronic components is pivotal for large-scale devices. However, electronic building blocks that simultaneously offer low energy consumption, fast switching, low error rates, a small footprint and simple fabrication remain elusive. In this work, we demonstrate a superconducting switch with attojoule switching energy, high speed (pico-second rise/fall times), and high integration density (on the order of $10^{-2}$ $\mathrm{μm^2}$ per switch). The switch consists of a superconducting channel and a metal heater separated by an insulating silica layer, prepared using lift-off techniques. We experimentally demonstrate digital gate operations utilizing this technology, such as NOT, NAND, NOR, AND, and OR gates, with a few femtojoule energy consumption and ultralow bit error rates < $10^{-8}$. In addition, we build volatile memory elements with few femtojoule energy consumption per operation, a nanosecond operation speed, and a retention time over $10^5$ s. These superconducting switches open new possibilities for increasing the size and complexity of modern cryogenic technologies.

physics.app-ph↗

arXiv2023

Deep mouse brain two-photon near-infrared fluorescence imaging using a superconducting nanowire single-photon detector array

Two-photon microscopy (2PM) has become an important tool in biology to study the structure and function of intact tissues in-vivo. However, adult mammalian tissues such as the mouse brain are highly scattering, thereby putting fundamental limits on the achievable imaging depth, which typically resides around 600-800um. In principle, shifting both the excitation as well as (fluorescence) emission light to the shortwave near-infrared (SWIR, 1000-1700 nm) region promises substantially deeper imaging in 2PM, yet has proven challenging in the past due to the limited availability of detectors and probes in this wavelength region. To overcome these limitations and fully capitalize on the SWIR region, in this work we introduce a novel array of superconducting nanowire single-photon detectors (SNSPDs) and associated custom detection electronics for the use in near-infrared 2PM. The SNSPD array exhibits high efficiency and dynamic range, as well as low dark-count rates over a wide wavelength range. Additionally, the electronics and software permit seamless integration into typical 2PM systems. Together with a fluorescent dye emitting at 1105 nm, we report imaging depth of > 1.1mm in the in-vivo mouse brain, limited only by available labeling density and laser power. Our work further establishes SWIR 2PM approaches and SNSPDs as promising technologies for deep tissue biological imaging.

physics.optics↗

arXiv2020

Detecting Infrared Single Photons with Near-Unity System Detection Efficiency

Single photon detectors are indispensable tools in optics, from fundamental measurements to quantum information processing. The ability of superconducting nanowire single photon detectors to detect single photons with unprecedented efficiency, short dead time and high time resolution over a large frequency range enabled major advances in quantum optics. However, combining near-unity system detection efficiency with high timing performance remains an outstanding challenge. In this work, we show novel superconducting nanowire single photon detectors fabricated on membranes with 94-99.5 (plus minus 2.07%) system detection efficiency in the wavelength range 1280-1500 nm. The SiO2/Au membrane enables broadband absorption in small SNSPDs, offering high detection efficiency in combination with high timing performance. With low noise cryogenic amplifiers operated in the same cryostat, our efficient detectors reach timing jitter in the range of 15-26 ps. We discuss the prime challenges in optical design, device fabrication as well as accurate and reliable detection efficiency measurements to achieve high performance single-photon detection. As a result, the fast-developing fields of quantum information science, quantum metrology, infrared imaging and quantum networks will greatly benefit from this far-reaching quantum detection technology.

quant-ph↗