相关论文: Magnetism in SQUIDs at Millikelvin Temperatures
Magnetic flux structure on the surface of EuFe$_2$(As$\rm_{1-x}$P$\rm_x$)$_2$ single crystals with nearly optimal phosphorus doping levels $x=0.20$, and $x=0.21$ is studied by low-temperature magnetic force microscopy and decoration with…
The accurate analytical solution for the low temperature $1/f$ noise in a microwave dielectric constant of amorphous films containing tunneling two-level systems (TLSs) is derived within the standard tunneling model including the weak…
We present a parallel network of 16 demagnetization refrigerators mounted on a cryofree dilution refrigerator aimed to cool nanoelectronic devices to sub-millikelvin temperatures. To measure the refrigerator temperature, the thermal motion…
We present theoretical studies of temperature dependent diamagnetic-paramagnetic transitions in thin quantum rings. Our studies show that the magnetic susceptibility of metal/semiconductor rings can exhibit multiple sign flips at…
Consistent with the predictions of Kibble and Zurek, scaling behaviour has been seen in the production of fluxoids during temperature quenches of superconducting rings. However, deviations from the canonical behaviour arise because of…
When a superconducting radiofrequency cavity is cooled through its critical temperature, ambient magnetic flux can become "frozen in" to the superconductor, resulting in degradation of the quality factor. This is especially problematic in…
We show that an adiabatic increase of the supercurrent along a superconductor with lines of nodes of the order parameter on the Fermi surface can result in a cooling effect. The maximum cooling occurs if the supercurrent increases up to its…
Fully conductive band tails cause the subthreshold swing to saturate at temperatures above 1 K. However, recent measurements indicate that below 1 K, the subthreshold swing in certain MOSFET structures resumes a linear scaling with…
We investigate the effect of thermal fluctuations on the (mean-field) Abrikosov phase. The lower critical dimension of the superconducting phase is three, indicating the absence of the Abrikosov phase for dimensions d<3. Within the d=3…
Here we find the increase in 1/f noise of superconducting resonators at low temperatures to be completely incompatible with the standard tunneling model (STM) of Two Level Systems (TLS), which has been used to describe low-frequency noise…
We report a study of the low temperature bulk magnetic properties of the spin ice compound Dy2Ti2O7 with particular attention to the (T < 4 K) spin freezing transition. While this transition is superficially similar to that in a spin glass,…
High-temperature conventional superconductivity in hydrogen-rich materials under high pressure has been reportedly found in twelve different compounds in recent years. However, the experimental evidence on which these claims are based has…
We report a scanning superconducting quantum interference device (SQUID) microscope in a cryogen-free dilution refrigerator with a base temperature at the sample stage of at least 30 mK. The microscope is rigidly mounted to the mixing…
We show that some experimentally observed features of vortex matter in high temperature superconductors may be interpreted in simpler ways than it is usually done. In particular, we consider magnetic flux creep at low temperatures as well…
We explore a small quantum refrigerator consisting of three qubits, each of which is kept in contact with an environment. We consider two settings: one is when there is necessarily transient cooling and the other is when both steady-state…
Trapped magnetic vortices in niobium introduce microwave losses that degrade the performance of superconducting resonators. While such losses have been extensively studied above 1~K, we report here their direct quantification in the…
The physics of interacting nuclear spins arranged in a crystalline lattice is typically described using a thermodynamic framework: a variety of experimental studies in bulk solid-state systems have proven the concept of a spin temperature…
We investigate the 1/f noise properties of epitaxial graphene devices at low temperatures as a function of temperature, current and magnetic flux density. At low currents, an exponential decay of the 1/f noise power spectral density with…
We report the observation of a weak spontaneous magnetic field appearing at the transition temperature of $\rm YBa_2Cu_3O_{7-\delta}$ into the superconducting state. The effect is observed in 14 out of 15 epitaxial films grown on different…
In Fig. 4c, under the section titled "Pinning and thermally activated motion of vortices" in arXiv:2206.14108 and Nat Phys. 19, 1293 (2023) [1], Minkov and co-workers presented the time dependence of the magnetic moment of sulfur hydride…