相关论文: SQUID magnetometer based on Grooved Dayem nanobrid…
SQUID-embedded superconducting resonators are of great interest due to their potential for coupling highly scalable superconducting circuits with quantum memories based on solid-state spin ensembles. Such an application requires a high-$Q$,…
We study the coupled current and magnetization noise in magnetic nanostructures by magnetoelectronic circuit theory. Spin current fluctuations, which depend on the magnetic configuration, are found to be an important source of magnetization…
Superconducting qubits with in-situ tunable properties are important for constructing a quantum computer. Qubit tunability, however, often comes at the expense of increased noise sensitivity. Here, we propose a flux-tunable superconducting…
In this work, we develop a nanoscale magnetic field sensor based on a spin-Hall nano-oscillator (SHNO) device. We fabricate constriction-based SHNO devices using Ni$_{81}$Fe$_{19}$/Au$_{0.25}$Pt$_{0.75}$ bilayer and use them to demonstrate…
We recently demonstrated a 1$^{\textrm{st}}$-order axial gradiometer SQUID system, which is operated in a liquid He dewar with negligible noise contribution. The achieved close to SQUID-limited measured coupled energy sensitivity…
Micron-sized superconducting interference devices ($\mu$-SQUIDs) based on constrictions optimized for minimizing thermal runaway are shown to exhibit voltage oscillations with applied magnetic flux despite their hysteretic behavior. We…
Scanning superconducting quantum interference device microscopy (sSQUID) is currently one of the most effective methods for direct and sensitive magnetic flux imaging on the mesoscopic scale. A SQUID-on-chip design allows integration of…
Studying nanoscale dynamics is essential for understanding quantum materials and advancing quantum chip manufacturing. Still, it remains a major challenge to measure non-equilibrium properties such as current and dissipation, and their…
We have developed and measured a high-gain quantum-limited microwave parametric amplifier based on a superconducting lumped LC resonator with the inductor L including an array of 8 superconducting quantum interference devices (SQUIDs). This…
We have developed a nuclear magnetic resonance spectrometer with a series tuned input circuit for measurements on samples at millikelvin temperatures based on an integrated two-stage superconducting quantum interference device current…
This work investigates the behavior of a spin-exchange relaxation-free (SERF) magnetometer integrated into the feedback branch of a closed-loop control circuit, designed to actively suppress noise from a current source. In this…
It is sketched how a monostable rf- or dc-SQUID can mediate an inductive coupling between two adjacent flux qubits. The nontrivial dependence of the SQUID's susceptibility on external flux makes it possible to continuously tune the induced…
Scanning nanoscale superconducting quantum interference devices (SQUIDs) are gaining interest as highly sensitive microscopic magnetic and thermal characterization tools of quantum and topological states of matter and devices. Here we…
Recent experiments implicate spins on the surface of metals as the source of flux noise in SQUIDs, and indicate that these spins are able to relax without conserving total magnetization. We present a model of $1/f$ flux noise in which…
We present a portable optically pumped magnetometer instrument for ultra-sensitive measurements within the Earth's magnetic field. The central part of the system is a sensor head operating a MEMS-based Cs vapor cell in the light-shift…
We report on measurements of flux and charge noise in an rf-SQUID flux qubit using macroscopic resonant tunneling (MRT). We measure rates of incoherent tunneling from the lowest energy state in the initial well to the ground and first…
In applications for high-Tc superconducting DC-SQUIDs such as biomagnetism, nondestructive evaluation and the relaxation of magnetic nanoparticles, it is important to maintain reliable sensor performance over an extended time period. We…
Magnetic flux noise is a dominant source of dephasing and energy relaxation in superconducting qubits. The noise power spectral density varies with frequency as $1/f^\alpha$ with $\alpha \sim 1$ and spans 13 orders of magnitude. Recent work…
Superconducting QUantum-Interference Devices (SQUIDs) make magnetic resonance imaging (MRI) possible in ultra-low microtesla-range magnetic fields. In this work, we investigate the design parameters affecting the signal and noise…
The effect of thermal fluctuations on the behaviuor of a 4-terminal SQUID is investigated. The studied system consists of the Josephson 4-terminal junction with two terminals short-circuited by a superconducting ring and other two form the…