Wideband superconducting nanotube electrometer

Abstract

We have investigated the microwave response of nanotube Josephson junctions at 600-900 MHz at microwave powers corresponding to currents from 0 to $2\times I_{\mathrm{C}}$ in the junction. Compared with theoretical modeling, the response of the junctions correspond well to the lumped element model of resistively and capacitively shunted junction. We demonstrate the operation of these superconducting FETs as charge detectors at high frequencies without any matching circuits. Gate-voltage-induced charge $Q_{\mathrm{G}}$ modifies the critical current $I_{\mathrm{C}}$, which changes the effective impedance of the junction under microwave irradiation. This change, dependent on the transfer characteristics $d{I}_{\mathrm{C}}/d{Q}_{\mathrm{G}}$, modifies the reflected signal and it can be used for wide band electrometry. We measure a sensitivity of $3.1\times 10^{-5}$ $e/\sqrt{\mathrm{Hz}}$ from a sample which has a maximum switching current of 2.6 nA.

arXiv comment4 pages, 4 figures

References in corpus (10)

• Quantum supercurrent transistors in carbon nanotubes
• High-Tc superconductivity in entirely end-bonded multi-walled carbon nanotubes
• Even-odd effect in Andreev Transport through a Carbon Nanotube Quantum Dot
• Electron transport in single wall carbon nanotube weak links in the Fabry-Perot regime
• Quantum transport through carbon nanotubes: proximity induced and intrinsic superconductivity
• Superconductivity-enhanced bias spectroscopy in carbon nanotube quantum dots
• Coupling carbon nanotube mechanics to a superconducting circuit
• Gate-controlled superconductivity in diffusive multiwalled carbon nanotube
• Gate-tuned high frequency response of carbon nanotube Josephson junctions
• Conductance properties of nanotubes coupled to superconducting leads: signatures of Andreev states dynamics