Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Advanced Quantum Technologies

On‐Chip Cryogenic Level Meters for Magnetic Field Based on TiN Superconducting Microwave Resonators

Shu-Kun Ye, Zi‐Qing Huang, Yong-Qiang Xu, Yuan Kang, Rui Wu, Song-Yan Deng, Bao‐Chuan Wang, Ran-Ran 冉冉 Cai 蔡, Hai‐Ou Li, Xiang‐Xiang Song, Gang Cao, Guo‐Ping Guo

Published Sep 1, 2026• 0 citations
Publisher

Abstract

ABSTRACT Precise control of the external magnetic field orientation with respect to quantum devices is of particular importance since the field orientation can significantly influence quantum states. Therefore, in situ calibration of rotational misalignment of the magnetic field at cryogenic temperatures, where quantum devices are usually operated, is essential, yet remains largely unexplored. Here, leveraging the advantages of low microwave loss and high critical field, we demonstrate that high‐quality TiN nanowire superconducting microwave resonators exhibit sensitive and anisotropic responses to varied magnetic fields, enabling three‐dimensional calibration of the field orientation using a single device. Based on a developed tensor model, we extract competitive out‐of‐plane orientation calibration uncertainty of . Our approach maps the magnetic field to a readily measurable scalar parameter, thereby providing a reliable, repeatable, and efficient method for precisely quantifying field orientation, a capability highly desirable in research fields such as condensed matter physics and quantum computation.

DOI
10.1002/qute.70464

Related papers

Cover Feature: On‐Chip Cryogenic Level Meters for Magnetic Field Based on TiN Superconducting Microwave Resonators (Adv. Quantum Technol. 10/2026)

Shu‐Kun Ye, Zi‐Qing Huang, Yongqiang Xu +9 more

Under an external magnetic field, a high-quality TiN nanowire superconducting microwave resonator exhibits anisotropic frequency shifts as the field orientation rotates, mapping a peanut-like surface whose principal axes coincide with the device coordinate system. This enables precisely quantifying the field orientation relative to the resonator at cryogenic temperatures with a single device, a capability highly desirable for quantum information applications. More in article number e70464, Xiang-Xiang Song, Gang Cao, and co-workers.

Advanced Quantum Technologies•Oct 1, 2026•0 citations

Cryogenic single-port calibration for superconducting microwave resonator measurements

H. Wang, Suren Singh, Corey Rae McRae +8 more

Abstract Superconducting circuit testing and materials loss characterization requires robust and reliable methods for the extraction of internal and coupling quality factors of microwave resonators. A common method, imposed by limitations on the device design or experimental configuration, is the single-port reflection geometry, i.e. reflection-mode. However, impedance mismatches in cryogenic systems must be accounted for through calibration of the measurement chain while it is at low temperatures. In this paper, we demonstrate a data-based, single-port calibration using commercial microwave standards and a vector network analyzer with samples at millikelvin temperature in a dilution refrigerator, making this method useful for measurements of quantum phenomena. Finally, we cross reference our data-based, single-port calibration and reflection measurement with over-coupled 2D- and 3D-resonators against well established two-port techniques corroborating the validity of our method.

arXiv:2103.01491•Quantum Science and Technology•Jun 1, 2021•34 citations

Analysis and calibration techniques for superconducting resonators

Giuseppe Cataldo, Edward J. Wollack, Emily M. Barrentine +3 more

A method is proposed and experimentally explored for in-situ calibration of complex transmission data for superconducting microwave resonators. This cryogenic calibration method accounts for the instrumental transmission response between the vector network analyzer reference plane and the device calibration plane. Once calibrated, the observed resonator response is analyzed in detail by two approaches. The first, a phenomenological model based on physically realizable rational functions, enables the extraction of multiple resonance frequencies and widths for coupled resonators without explicit specification of the circuit network. In the second, an ABCD-matrix representation for the distributed transmission line circuit is used to model the observed response from the characteristic impedance and propagation constant. When used in conjunction with electromagnetic simulations, the kinetic inductance fraction can be determined with this method with an accuracy of 2%. Datasets for superconducting microstrip and coplanar-waveguide resonator devices were investigated and a recovery within 1% of the observed complex transmission amplitude was achieved with both analysis approaches. The experimental configuration used in microwave characterization of the devices and self-consistent constraints for the electromagnetic constitutive relations for parameter extraction are also presented.

arXiv:1411.1343•Review of Scientific Instruments•Jan 1, 2015•17 citations

Watching a Superconducting Coplanar Waveguide Heat Up with a Single Color Center

Ioannis Karapatzakis, Jeremias Resch, David Hunger +1 more

Single color centers in diamond offer a local probe of their cryogenic environment, providing a direct way to quantify heating in spin-control hardware. Here, we establish a single spectrally stable tin-vacancy (SnV) center as an on-chip thermometer for a diamond membrane and use it to characterize microwave- and radio-frequency-induced heating in a superconducting coplanar waveguide patterned on the same chip. We first calibrate the temperature dependence of the optical C-transition frequency and linewidth from $20\,\mathrm{K}$ down to the few-kelvin regime. At lower temperatures, where the optical response becomes weakly temperature dependent, we use the spin-lattice relaxation time $T_1$ as a complementary thermometer and tune its sensitivity with the transverse magnetic-field component. Applying this local thermometer to a niobium coplanar waveguide, we observe magnetic-field-dependent superconducting breakdown under GHz drive, accompanied by abrupt heating of the diamond. In contrast, at $20\,\mathrm{MHz}$ and $400\,\mathrm{mT}$, relevant for nuclear-spin control, we detect no measurable heating up to the breakdown threshold of $9.4\,\mathrm{dBm}$, corresponding to $B_\mathrm{ac}\sim1.2\,\mathrm{mT}$. These results define a safe operating window for superconducting microwave and RF control structures in diamond-based quantum nodes.

quant-pharXiv:2606.15398•Jun 16, 2026•0 citations

Measurement Techniques for Superconducting Microwave Resonators Towards Quantum Device Applications

Corey Rae McRae

Superconducting qubits, though promising for both near-term problem-solving as well as the development of large-scale quantum computing systems, are limited in performance largely by materials-induced decoherence channels which are maximized at millikelvin temperatures, single photon powers, and microwave frequencies. Superconducting microwave resonators are ideal tools for measuring these materials losses due to their simplicity, well-understood behavior, and sensitivity to these same losses. In order to better understand and mitigate dominant qubit decoherence channels, accurate and precise characterization of superconducting microwave resonator performance is critical. In this paper, current measurement techniques for superconducting microwave resonators are discussed, including experimental set-up, error analysis, and cryogenic calibration of a vector network analyzer.

IEEE MTT-S International Microwave Symposium digest•Jun 19, 2022•3 citations

Tunable Resonator Integrated Magnetometry

Colin Stack, Brian Sears, Aruna Ramanayaka +3 more

The quantum-technology revolution is reshaping computing, sensing, and communication. In magnetometry, recent advances leverage precise control of spin qubits and color centers in solid-state crystals for mesoscopic-scale sensing. Yet at very low temperatures, superconducting sensing technology remains unrivaled because of its non-invasiveness and higher sensitivity. Here we describe a class of superconducting sensors that offers low loss and quantum non-demolition measurement characteristics. We designed and fabricated a superconducting flux-tunable resonator (tRes) in a superconducting chip foundry and matured it to a level that combines the speed of an inductor-capacitor circuit with the flux sensitivity of a superconducting quantum interference device (SQUID) to perform magnetometry at milli-kelvin temperature to investigate targets. We introduce its fundamental functionality readily at MHz magnetic sampling rate, showcase two measurement modalities, and investigate three circuits with gradually increasing complexity to extract target-specific information. The combination of high sensitivity and fast readout characteristics make tRes an attractive and versatile magnetometer.

cond-mat.mes-hallCross-listedarXiv:2606.04914•Jun 4, 2026•0 citations
ABSTRACT Precise control of the external magnetic field orientation with respect to quantum devices is of particular importance since the field orientation can significantly influence quantum states. Therefore, in situ calibration of rotational misalignment of the magnetic field at cryogenic temperatures, where quantum devices are usually operated, is essential, yet remains largely unexplored. Here, leveraging the advantages of low microwave loss and high critical field, we demonstrate that high‐quality TiN nanowire superconducting microwave resonators exhibit sensitive and anisotropic responses to varied magnetic fields, enabling three‐dimensional calibration of the field orientation using a single device. Based on a developed tensor model, we extract competitive out‐of‐plane orientation calibration uncertainty of . Our approach maps the magnetic field to a readily measurable scalar parameter, thereby providing a reliable, repeatable, and efficient method for precisely quantifying field orientation, a capability highly desirable in research fields such as condensed matter physics and quantum computation.
Under an external magnetic field, a high-quality TiN nanowire superconducting microwave resonator exhibits anisotropic frequency shifts as the field orientation rotates, mapping a peanut-like surface whose principal axes coincide with the device coordinate system. This enables precisely quantifying the field orientation relative to the resonator at cryogenic temperatures with a single device, a capability highly desirable for quantum information applications. More in article number e70464, Xiang-Xiang Song, Gang Cao, and co-workers.
Abstract Superconducting circuit testing and materials loss characterization requires robust and reliable methods for the extraction of internal and coupling quality factors of microwave resonators. A common method, imposed by limitations on the device design or experimental configuration, is the single-port reflection geometry, i.e. reflection-mode. However, impedance mismatches in cryogenic systems must be accounted for through calibration of the measurement chain while it is at low temperatures. In this paper, we demonstrate a data-based, single-port calibration using commercial microwave standards and a vector network analyzer with samples at millikelvin temperature in a dilution refrigerator, making this method useful for measurements of quantum phenomena. Finally, we cross reference our data-based, single-port calibration and reflection measurement with over-coupled 2D- and 3D-resonators against well established two-port techniques corroborating the validity of our method.
A method is proposed and experimentally explored for in-situ calibration of complex transmission data for superconducting microwave resonators. This cryogenic calibration method accounts for the instrumental transmission response between the vector network analyzer reference plane and the device calibration plane. Once calibrated, the observed resonator response is analyzed in detail by two approaches. The first, a phenomenological model based on physically realizable rational functions, enables the extraction of multiple resonance frequencies and widths for coupled resonators without explicit specification of the circuit network. In the second, an ABCD-matrix representation for the distributed transmission line circuit is used to model the observed response from the characteristic impedance and propagation constant. When used in conjunction with electromagnetic simulations, the kinetic inductance fraction can be determined with this method with an accuracy of 2%. Datasets for superconducting microstrip and coplanar-waveguide resonator devices were investigated and a recovery within 1% of the observed complex transmission amplitude was achieved with both analysis approaches. The experimental configuration used in microwave characterization of the devices and self-consistent constraints for the electromagnetic constitutive relations for parameter extraction are also presented.
Single color centers in diamond offer a local probe of their cryogenic environment, providing a direct way to quantify heating in spin-control hardware. Here, we establish a single spectrally stable tin-vacancy (SnV) center as an on-chip thermometer for a diamond membrane and use it to characterize microwave- and radio-frequency-induced heating in a superconducting coplanar waveguide patterned on the same chip. We first calibrate the temperature dependence of the optical C-transition frequency and linewidth from 20 K20\,\mathrm{K}20K down to the few-kelvin regime. At lower temperatures, where the optical response becomes weakly temperature dependent, we use the spin-lattice relaxation time T1T_1T1​ as a complementary thermometer and tune its sensitivity with the transverse magnetic-field component. Applying this local thermometer to a niobium coplanar waveguide, we observe magnetic-field-dependent superconducting breakdown under GHz drive, accompanied by abrupt heating of the diamond. In contrast, at 20 MHz20\,\mathrm{MHz}20MHz and 400 mT400\,\mathrm{mT}400mT, relevant for nuclear-spin control, we detect no measurable heating up to the breakdown threshold of 9.4 dBm9.4\,\mathrm{dBm}9.4dBm, corresponding to Bac∼1.2 mTB_\mathrm{ac}\sim1.2\,\mathrm{mT}Bac​∼1.2mT. These results define a safe operating window for superconducting microwave and RF control structures in diamond-based quantum nodes.
Superconducting qubits, though promising for both near-term problem-solving as well as the development of large-scale quantum computing systems, are limited in performance largely by materials-induced decoherence channels which are maximized at millikelvin temperatures, single photon powers, and microwave frequencies. Superconducting microwave resonators are ideal tools for measuring these materials losses due to their simplicity, well-understood behavior, and sensitivity to these same losses. In order to better understand and mitigate dominant qubit decoherence channels, accurate and precise characterization of superconducting microwave resonator performance is critical. In this paper, current measurement techniques for superconducting microwave resonators are discussed, including experimental set-up, error analysis, and cryogenic calibration of a vector network analyzer.
The quantum-technology revolution is reshaping computing, sensing, and communication. In magnetometry, recent advances leverage precise control of spin qubits and color centers in solid-state crystals for mesoscopic-scale sensing. Yet at very low temperatures, superconducting sensing technology remains unrivaled because of its non-invasiveness and higher sensitivity. Here we describe a class of superconducting sensors that offers low loss and quantum non-demolition measurement characteristics. We designed and fabricated a superconducting flux-tunable resonator (tRes) in a superconducting chip foundry and matured it to a level that combines the speed of an inductor-capacitor circuit with the flux sensitivity of a superconducting quantum interference device (SQUID) to perform magnetometry at milli-kelvin temperature to investigate targets. We introduce its fundamental functionality readily at MHz magnetic sampling rate, showcase two measurement modalities, and investigate three circuits with gradually increasing complexity to extract target-specific information. The combination of high sensitivity and fast readout characteristics make tRes an attractive and versatile magnetometer.