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Abstract Van der Waals (vdW) superconductors remain superconducting down to the monolayer limit, enabling the exploration of emergent physical phenomena and functionality driven by reduced dimensionality. Here, we report the characterization of the kinetic inductance of atomically thin NbSe2, a two-dimensional van der Waals superconductor, using superconducting coplanar waveguides and microwave measurement techniques familiar to circuit quantum electrodynamics (cQED). The kinetic inductance scales inversely with the number of NbSe2layers, reaching 1.2 nH/□in the monolayer limit. Furthermore, the measured kinetic inductance exhibits a thickness-dependent crossover from clean- to dirty-limit behavior, with enhanced dirty-limit contributions emerging in the ultra-thin regime. These effects are likely driven by increased surface scattering, multi-band superconductivity, and geometric confinement. Additionally, the self-Kerr nonlinearity of the NbSe2films ranges fromK/2π= −0.006 to −14.7 Hz/photon, indicating its strong potential in applications requiring compact, nearly linear, high-inductance superconducting quantum devices and detectors. The fabrication and characterization techniques demonstrated here are extensible to the investigation of other two-dimensional superconductors.
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This content will become publicly available on August 13, 2027
Encapsulation epitaxy of air-stable 2D superconductors for quantum circuits
Not AvailableTwo-dimensional (2D) superconductors are emerging platforms supporting both strongly correlated physics and quantum information science1,2. Their reduced dimensionality, atomically flat interfaces, and high-crystallinity are particularly attractive for realizing compact lumped-element devices in superconducting circuits3–5. However, large-scale synthesis of monolayer 2D superconductors remains challenging as they are easily oxidized in air6. Here, we report an “encapsulation epitaxy” mechanism that enables the growth of large-area (>1-inch), air-stable, monolayer NbSe2 films (1L-NbSe2) and explored their potential for superconducting quantum circuits. This work represents a distinct growth phenomenon in which a 2D encapsulation layer, such as graphene or hexagonal boron nitride (hBN), pre-deposited on a 3D substrate (e.g., SiO2, Si3N4) simultaneously serves as a template for the epitaxial growth of 1L-NbSe2 underneath it at encapsulation-substrate interface and as a protective capping layer against ambient degradation. The as-grown 1L-graphene/NbSe2 heterostructures exhibit robust superconductivity (superconducting transition temperature Tc ≈ 1 K) and enhanced charge density wave (CDW; CDW transition temperature TCDW ≈ 177 K). We further demonstrate the integration of 1L-NbSe2 into superconducting circuits by developing oxidation-free transfer and superconducting edge-contact techniques. The 1L-NbSe2 in these circuits feature a measured kinetic inductance LK ≈ 0.7 nH/□, making it suitable for quantum circuits requiring elements with high kinetic inductance. This encapsulation epitaxy methodology enables the production of air-stable 2D superconductors and van der Waals heterostructures, holding the promise for wafer-scale, monolithic fabrication of superconducting quantum circuitry.
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- Award ID(s):
- 2527588
- PAR ID:
- 10707384
- Author(s) / Creator(s):
- ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; more »
- Publisher / Repository:
- Nature
- Date Published:
- Journal Name:
- Nature
- Volume:
- 656
- Issue:
- 8127
- ISSN:
- 0028-0836
- Page Range / eLocation ID:
- 349 to 356
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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