Berezinskii–Kosterlitz–Thouless transition in an Al superconducting nanofilm grown on GaAs by molecular beam epitaxy

Su, Guan Ming; Wu, Bi; Fan, Yen Ting; Kumar, Ankit; Chang, Chau Shing; Yeh, Ching Chen; Patel, Dinesh K.; Lin, Sheng Di; Chow, Lee; Liang, Chi‐Te

doi:10.1088/1361-6528/ab71ba

Cited by 4 publications

(1 citation statement)

References 30 publications

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“…This behavior suggests the presence of Berezinskii-Kosterlitz-Thouless (BKT) transition, which was previously reported in the thermal-driven evolution of 2D superconductivity at finite temperatures 34 , 35 . Although the BKT transition typically occurs in materials with large sheet resistance 36 , this is not an exclusive requirement considering the relatively low sheet resistance in our case ( ) and in other 2D superconductors 35 , 37 , 38 . The BKT transition is further validated by the temperature induced vortices/antivortices unbinding model 38 , providing reasonable fittings of the observed R - T curves using the Halperin-Nelson formula 34 (Supplementary Fig.…”

Section: Resultsmentioning

confidence: 95%

Reversible modulation of superconductivity in thin-film NbSe2 via plasmon coupling

Cheng,

Lin,

Chen

et al. 2024

Nat Commun

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In recent years, lightwave has stood out as an ultrafast, non-contact control knob for developing compact superconducting circuitry. However, the modulation efficiency is limited by the low photoresponse of superconductors. Plasmons, with the advantages of strong light-matter interaction, present a promising route to overcome the limitations. Here we achieve effective modulation of superconductivity in thin-film NbSe2 via near-field coupling to plasmons in gold nanoparticles. Upon resonant plasmon excitation, the superconductivity of NbSe2 is substantially suppressed. The modulation factor exceeds 40% at a photon flux of 9.36 × 1013 s−1mm−2, and the effect is significantly diminished for thicker NbSe2 samples. Our observations can be theoretically interpreted by invoking the non-equilibrium electron distribution in NbSe2 driven by the plasmon-associated evanescent field. Finally, a reversible plasmon-driven superconducting switch is realized in this system. These findings highlight plasmonic tailoring of quantum states as an innovative strategy for superconducting electronics.

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Section: Resultsmentioning

confidence: 95%

Reversible modulation of superconductivity in thin-film NbSe2 via plasmon coupling

Cheng,

Lin,

Chen

et al. 2024

Nat Commun

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Ultra‐Shallow All‐Epitaxial Aluminum Gate GaAs/Al_xGa_1−xAs Transistors with High Electron Mobility

Alava

Wang

Chen

et al. 2021

Adv Funct Materials

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The electron mobility in shallow GaAs/AlxGa1−xAs heterostructures is strongly suppressed by charge wafer surface, which arises from native surface oxide layers formed when the wafer is removed from the crystal growth system. Here an in situ epitaxial aluminum gate, grown as part of the wafer, is used to eliminate surface charge scattering. Transmission electron microscope characterization shows that the in situ epitaxial aluminum is crystalline, and the wafer surface is free of native oxide. The influence of Al thickness and the use of different semiconductor wetting layers at the semiconductor‐aluminum interface are examined and correlated with electron mobility. The electron mobility is found to strongly depend on aluminum thickness. For 8 nm thick aluminum, the electron mobility is also influenced by the wetting layer, with aluminum grown on GaAs producing higher mobility compared to AlAs or Al0.33Ga0.67As wetting layers. The suppression of surface charge scattering in these all‐epitaxial devices allows for high mobilities across a wide density range despite the shallow conduction channel (35 nm below the gate). These measurements also provide a uniquely sensitive method of determining the electrical quality of the semiconductor–metal interface, relevant to the formation of hybrid semiconductor–superconductor devices.

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Disorder-induced 2D superconductivity in a NbTiN film grown on Si by ultrahigh-vacuum magneton sputtering

Chen¹,

Yang²,

Peng³

et al. 2022

Supercond. Sci. Technol.

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We report on the growth and characterization of a niobium titanium nitride (NbTiN) film on a Si substrate prepared by ultrahigh vacuum sputtering. We show that the superconducting transition temperature is lower than those of high-quality NbTiN films. Interestingly, even though the zero-temperature Ginzburg-Landau coherence length (=9.77 nm) is significantly shorter than the film thickness (=86 nm), we are still able to observe the Berezinskii-Kosterlitz-Thouless-like transition, indicating the two-dimensional (2D) signature of our three-dimensional (3D) sample. We propose that the mechanism of hidden 2D superconducting property is similar to the recently reported results of the disordered induced 3D to 2D superconductor transition. We suggest further theoretical work is required for studying our new experimental results.

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Berezinskii–Kosterlitz–Thouless transition in an Al superconducting nanofilm grown on GaAs by molecular beam epitaxy

Cited by 4 publications

References 30 publications

Reversible modulation of superconductivity in thin-film NbSe2 via plasmon coupling

Reversible modulation of superconductivity in thin-film NbSe2 via plasmon coupling

Ultra‐Shallow All‐Epitaxial Aluminum Gate GaAs/Al_xGa_1−xAs Transistors with High Electron Mobility

Disorder-induced 2D superconductivity in a NbTiN film grown on Si by ultrahigh-vacuum magneton sputtering

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Berezinskii–Kosterlitz–Thouless transition in an Al superconducting nanofilm grown on GaAs by molecular beam epitaxy

Cited by 4 publications

References 30 publications

Reversible modulation of superconductivity in thin-film NbSe2 via plasmon coupling

Reversible modulation of superconductivity in thin-film NbSe2 via plasmon coupling

Ultra‐Shallow All‐Epitaxial Aluminum Gate GaAs/AlxGa1−xAs Transistors with High Electron Mobility

Disorder-induced 2D superconductivity in a NbTiN film grown on Si by ultrahigh-vacuum magneton sputtering

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Product

Resources

About

Ultra‐Shallow All‐Epitaxial Aluminum Gate GaAs/Al_xGa_1−xAs Transistors with High Electron Mobility