A high-T _c van der Waals superconductor based photodetector with ultra-high responsivity and nanosecond relaxation time

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 × 104 V W−1, theoretically achievable noise equivalent power of 15.9 fW Hz1/2 and nanosecond relaxation times. At 15 K the detector reaches an ultra-high performance of 2.33 × 107 V W−1 and 55.2 aW Hz1/2. It is based on van der Waals heterostructures of the high temperature superconductor Bi2Sr2CaCu2O8+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.

Nanowire bolometer using a 2D high-temperature superconductor

“…shows the opposite behavior to that of the responsivity. The nanowire has maximum responsivity of 7.59 × 10 3 V/W at 62 K (This temperature is close to the knee of the S-N transition; resistance of the nanowire drops to zero at 67 K with zero bias), which is close to the other high-T c bolometers [34][35][36][37][38][39][40]. A comparison with the existing bolometers is drawn in the Supporting Information, Figure S7.…”

“…We note the NEP of our bolometer is comparatively higher than the earlier reported high-T c bolometers [34][35][36][37][38][39][40]. The major sources of noise that can results in higher NEP, are phonon noise, Johnson noise, amplifier noise, and excess 1/f noise generated by the superconducting material [42].…”

Two-dimensional cuprate nanodetector with single telecom photon sensitivity at T = 20 K

“…The full recovery time of the device lasts about 2 milliseconds. The observed τ is much slower than the reset time of conventional SNSPD's (~ 𝑛𝑠) [2,3] and the reported intrinsic photoresponse time of cuprate superconductors [26,34]. This slow relaxation time is consistent across all devices (Fig.…”

“…We explore an alternative approach based on exfoliated, 2D cuprate Bi2Sr2CaCu2O8-δ (BSCCO). Novel fabrication methods allow us to harness the pristine superconducting properties of few-layer BSCCO [24][25][26]. We report multiple nanostructures with sharp, hysteretic I-V characteristics combined with high TC (70 -80 K).…”

Revealing the Thermal Properties of Superconducting Magic-Angle Twisted Bilayer Graphene

“…To date, the most sensitive detectors for electromagnetic radiation are based on superconducting materials and exploit local photoinduced heating across their strongly temperature dependent superconducting transition. − To maximize the temperature increase due to absorbed radiation, the key requirements for such materials are an ultralow electronic heat capacity ( C e ), which is typically achieved using nanostructured thin films, as well as a good thermal isolation and ultralow thermal conductance ( G th ) to its surroundings . Possessing both of these attributes, graphene has recently attracted formidable attention. − While not an intrinsic superconductor, it can be placed in the proximity of superconducting electrodes to form Josephson junctions and as such be successfully used as a GHz bolometer , and mid-IR single-photon detector. , Furthermore, the recently discovered moiré material, magic-angle twisted bilayer graphene (MATBG) was shown to have an intrinsic, gate tunable superconducting phase with a record-low carrier density ( n ) of <10 11 cm –2 and C e < 100 k B , , where k B is the Boltzmann constant.…”