Ultra-high-ohmic microstripline resistors for Coulomb blockade devices

TL;DR

This paper presents the development and low-temperature testing of ultra-high-ohmic microstrip resistors made of weakly oxidized titanium, achieving high resistivity and promising low-noise properties for Coulomb blockade and quantum current standards.

Contribution

It introduces a new fabrication method for titanium resistors with higher resistivity and linearity at millikelvin temperatures, enhancing high-impedance environments for quantum devices.

Findings

Resistors with sheet resistivity up to 7 kΩ were achieved.

Nearly linear I-V characteristics observed down to 20 mK.

Resistors show potential for low-noise applications in quantum standards.

Abstract

In this paper, we report on the fabrication and the low-temperature characterization of extremely high-ohmic microstrip resistors made of a thin film of weakly oxidized titanium. Nearly linear voltage-current characteristics were measured at temperatures down to $T \sim \unit[20]{mK}$ for films with sheet resistivity up to as high as $\sim \unit[7]{k\Omega}$, i.e. about an order of magnitude higher than our previous findings for weakly oxidized Cr. Our analysis indicates that such an improvement can help to create an advantageous high-impedance environment for different Coulomb blockade devices. Further properties of the Ti film addressed in this work show a promise of low-noise behavior of the resistors when applied in different realizations of the quantum standard of current.