A liquid nitrogen cooled superconducting transition edge sensor with ultra-high responsivity and GHz operation speeds
Paul Seifert, José Ramón Durán Retamal, Rafael Luque Merino, Hanan Herzig Sheinfux, John N. Moore, Mohammed Ali Aamir, Takashi Taniguchi, Kenji Wantanabe, Kazuo Kadowaki, M. Artiglia, M. Romagnoli, Dmitri K. Efetov
Photodetectors based on nano-structured superconducting thin films are currently some of the most sensitive quantum sensors and are key enabling technologies in such broad areas as quantum information, quantum computation and radio-astronomy. However, their broader use is held back by the low operation temperatures which require expensive cryostats. Here, we demonstrate a nitrogen cooled superconducting transition edge sensor, which shows orders of magnitude improved performance characteristics of any superconducting detector operated above 77K, with a responsivity of 9.61x10^4 V/W, noise equivalent power of 15.9 fW/Hz-1/2 and operation speeds up to GHz frequencies. It is based on van der Waals heterostructures of the high temperature superconductor Bi2Sr2CaCu2O8, which are shaped into nano-wires with ultra-small form factor. To highlight the versatility of the detector we demonstrate its fabrication and operation on a telecom grade SiN waveguide chip. Our detector significantly relaxes the demands of practical applications of superconducting detectors and displays its huge potential for photonics based quantum applications.
Photodetectors based on nano-structured superconducting thin films are currently some of the most sensitive quantum sensors and are key enabling technologies in such broad areas as quantum information, quantum computation and radio-astronomy. However, their broader use is held back by the low operation temperatures which require expensive cryostats. Here, we demonstrate a nitrogen cooled superconducting transition edge sensor, which shows orders of magnitude improved performance characteristics of any superconducting detector operated above 77K, with a responsivity of 9.61x10^4 V/W, noise equivalent power of 15.9 fW/Hz-1/2 and operation speeds up to GHz frequencies. It is based on van der Waals heterostructures of the high temperature superconductor Bi2Sr2CaCu2O8, which are shaped into nano-wires with ultra-small form factor. To highlight the versatility of the detector we demonstrate its fabrication and operation on a telecom grade SiN waveguide chip. Our detector significantly relaxes the demands of practical applications of superconducting detectors and displays its huge potential for photonics based quantum applications.
Abstract Photodetectors based on nano-structured superconducting thin films are currently some of the most sensitive quantum sensors and are key enabling technologies in such broad areas as quantum information, quantum computation and radio-astronomy. However, their broader use is held back by the low operation temperatures which require expensive cryostats. Here, we demonstrate a high- T c superconducting photodetector, which shows orders of magnitude improved performance characteristics of any superconducting detector operated above 77 K, with a responsivity of 9.61 × 10 4 V W −1 , theoretically achievable noise equivalent power of 15.9 fW Hz 1/2 and nanosecond relaxation times. At 15 K the detector reaches an ultra-high performance of 2.33 × 10 7 V W −1 and 55.2 aW Hz 1/2 . It is based on van der Waals heterostructures of the high temperature superconductor Bi 2 Sr 2 CaCu 2 O 8+ δ , which are shaped into nano-wires with ultra-small form factor using focused helium ion beam irradiation. To highlight the versatility of the detector we demonstrate its fabrication and operation on a telecom grade SiN waveguide chip. Our detector significantly relaxes the demands of practical applications of superconducting detectors and displays its possible potential for photonics based quantum applications.
Superconducting single-photon detectors have been shown to have extremely high detection efficiency over a large wavelength range, typically exceeding 90 % [1, 2]. Their use in quantum and classical optics is becoming more and more widespread in part due to improvements to and ease of use of the cryogenic packaging. In this talk, we will review two superconducting detector technologies, the superconducting nanowire single-photon detector (SNSPD) and the optical transition-edge sensor (TES) [3], that are being developed at NIST. We will also describe their applications in quantum and classical optics and present our recent effort to use these detectors as calibration standards, as well as our effort to establish a single-photon detector calibration service. Superconducting Nanowire Single Photon Detectors The SNSPD is based on a meandering, narrow, thin superconducting nanowire, current-biased close to its critical current. Our SNSPDs operate at temperatures around 1K. When a photon is absorbed in the detection region, the energy deposited drives the wire normal and a voltage pulse can be observed. Due to the speed of the detection process, the SNSPD offers high timing resolution along with detection of the photon flux at the shot-noise limit. The combination of both these features yields a detector that can measure the photon’s arrival time from a faint object or source. SNSPDs also offer single-photon detection capability beyond the wavelength detection range of silicon and InGaAs, out to at least 5000 nm [4]. SNSPDs were also recently implemented in an 8×8-pixel array enabling low-resolution, real-time imaging [5]. For our calibration service effort, we built an SNSPD system that can be used as a transfer standard between labs for single-photon detector calibrations. Transition Edge Sensors In contrast to the SNSPD, the TES is a photon-number resolving detector that has almost unity detection efficiency. The TES consists of a superconducting thin film, voltage-biased so that its resistance is in the transition between the superconducting regime and the normal conducting regime. The steep slope of the resistive transition allows for small temperature changes to be measured. The TES is designed such that the absorption of a single photon increases the temperature of the superconducting film enough to discern the resulting signal from the TES system noise. Therefore, the TES needs to be electrically and thermally quiet and is generally operated at temperatures around 100 mK. Due to its energy resolving capability, the TES can be also used as a spectrally resolving single-photon detector with limited resolution [6]. The TES can also be operated as a cryogenic radiometer in combination with an electrical substitution method, and can, in principle, yield absolute calibration of optical powers on the order of a few tens of femtowatts [7]. References 1 A. E. Lita, A. J. Miller, and S. W. Nam, Opt. Express 16, 3032 (2008). 2 F. Marsili, et al., Nat Photon 7, 210 (2013). 3 R. Hadfield and G. Johansson, Superconducting Devices in Quantum Optics (Springer, 2016). 4 F. Marsili, et al., in CLEO: 2013 (OSA, San Jose, California, 2013), p. CTu1H.1. 5 M. S. Allman, et al., Applied Physics Letters 106, 192601 (2015). 6 M. Fortsch, et al., Journal of Optics 17, 065501 (2015). 7 N. A. Tomlin, J. H. Lehman, and S. Nam, Optics Letters 37, 2346 (2012).
Abstract Detecting light at the single-photon level is one of the pillars of emergent photonic technologies. This is realized through state-of-the-art superconducting detectors that offer efficient, broadband and fast response. However, the use of low T C superconducting thin films limits their operation temperature to approximately 4 K and below. Here, we demonstrate proof-of-concept nanodetectors based on exfoliated, two-dimensional cuprate superconductor Bi2Sr2CaCu2O8-δ that exhibit single-photon sensitivity at telecom wavelength at a record temperature of T = 20 K. These non-optimized devices exhibit a slow ∼ m s reset time and a low detection efficiency ( ∼ 10 − 4 ). We realize the elusive prospect of single-photon sensitivity on a high-T C nanodetector thanks to a novel approach, combining van der Waals fabrication techniques and a non-invasive nanopatterning based on light ion irradiation. This result paves the way for broader application of single-photon technologies, relaxing the cryogenic constraints for single-photon detection at telecom wavelength.
Detecting light at the single-photon level is one of the pillars of emergent photonic technologies. This is realized through state-of-the-art superconducting detectors that offer efficient, broadband and fast response. However, the use of superconducting thin films with low TC limits their operation temperature below 4K. In this work, we demonstrate proof-of-concept nanodetectors based on exfoliated, two-dimensional cuprate superconductor Bi2Sr2CaCu2O8-δ (BSCCO) that exhibit single-photon sensitivity at telecom wavelength at a record temperature of T = 20K. These non-optimized devices exhibit a slow (ms) reset time and a low detection efficiency (10^(-4)). We realize the elusive prospect of single-photon sensitivity on a high-TC nanodetector thanks to a novel approach, combining van der Waals fabrication techniques and a non-invasive nanopatterning based on light ion irradiation. This result paves the way for broader application of single-photon technologies, relaxing the cryogenic constraints for single-photon detection at telecom wavelength.
High performance optical photon detectors are indispensable for quantum communications. Superconducting detectors are very attractive because of their high quantum efficiency and intrinsic low dark count probability. We have been developing high performance optical photon detectors with a Titanium‐based transition edge sensor (Ti‐TES), which have superconducting critical temperatures around 300 mK. The relatively high transition temperature enables rapid thermal relaxation of the absorbed photon energy, resulting in excellent temporal characteristics such as fast response time below 1 μs, low timing jitter of 33 ns, and maximum counting rate over 1 MHz. Although there is a tradeoff relationship between the temporal response and energy resolution, we have simultaneously achieved high quantum efficiency and high energy resolution. We fabricated Ti‐TES devices with an optical cavity structure for photon absorption enhancement in the superconducting film. The measured quantum efficiency is over 95 % at 850 nm wavelength, and the energy resolution is 0.28 and 0.6 eV FWHM for the 5 μm and 10 μm square size devices, respectively, which is sufficient to resolve the photon number of the 850 nm light pulses. These high performance detectors are expected to be one of the powerful components in quantum information, communication and measurement technologies. We will also report and discuss the application of the Ti‐TES photon detectors to quantum communication systems.
Cryogenic systems are essential to many modern scientific and technological applications, including MRI superconducting magnets, particle accelerators, astrophysical detectors and quantum computing platforms, all of which operate at temperatures well below 120 K. In this framework, accurate temperature monitoring is, therefore, critical. However, conventional Resistance Temperature Detectors (RTDs) suffer from significant limitations in cryogenic environments, such as wiring complexity, power dissipation, limited low-temperature operation and large footprint, which restrict their integration in increasingly complex cryogenic infrastructures. Superconducting devices offer a promising alternative due to their high sensitivity at low temperatures, low power dissipation and compatibility with integrated quantum technologies. Inspired by Microwave Kinetic Inductance Detectors (MKIDs), this work investigates superconducting microwave resonators as minimally invasive, frequency-multiplexed cryogenic thermometers operating below 12 K. In particular, strategies to tune and enhance temperature sensitivity are explored by studying the effects of the superconducting thin-film thickness and surface nanostructuring. The first part of the study examines NbTi(N) planar resonators with thicknesses ranging from 20 nm to 150 nm, where temperature sensing is based on the temperature dependence of the kinetic inductance. S-shaped split-ring resonators resonating near 1.1 GHz are inductively coupled to a coplanar transmission line and characterized under cryogenic conditions. A clear trade-off between temperature sensitivity and quality factor is observed: thinner films achieve higher sensitivity, up to approximately 19 MHz/K for 20 nm thick devices, while the quality factor, typically exceeding 10^4, is found to degrade when the thickness is reduced. This trade-off leads to an optimal temperature resolution, with sub-microkelvin noise-equivalent temperature (NET) values. In particular, a minimum NET of (0.53±0.09) µK/Hz^(1/2) at 4.2 K is achieved for a 100 nm thick resonator, which is also exploited to study low-frequency temperature fluctuations in liquid helium. In the second part, a possible approach to enhance the temperature sensitivity, through surface nanostructuring, is investigated. Arrays of nanogaps are patterned in high-current regions of a 1.3 GHz resonator, in order to locally suppress superconductivity, reduce the critical temperature of the film and, therefore, accentuate the slope of the temperature-sensitive curve. These weak-links are realized by partially etching a 100 nm NbTi film, to leave 20-30 nm thick remaining nanogaps. Measurements reveal a significant increase in temperature sensitivity, reaching values as high as up to (62±1) MHz/K, which correspond to one order-of-magnitude improvement over non-nanostructured devices. Although this enhancement comes with increased noise-equivalent temperature, the results demonstrate the feasibility of engineering superconducting weak links to improve RF cryogenic thermometry and provide a solid foundation for future optimization. In reason of the achieved results, such an approach could find successful applications for a sub-µK high-resolution cryogenic temperature monitoring, specifically for integrated quantum architectures, further benefiting from the frequency-multiplexing that naturally arises from the multiple allocation of different superconducting microwave resonators.