A Thin-Film Cryotron Suitable For Use as an Ultra-Low-Temperature Switch.

Low-temperature superconducting circuits have become important for many scientific applications. However, there are presently no high current-capacity switches (~1 mA) with low power dissipation for sub-Kelvin operation. One candidate for a sub-Kelvin switch is the cryotron, a device in which the superconductivity of a wire is suppressed with a magnetic field.

Insensitivity of sub-Kelvin electron-phonon coupling to substrate properties.

We have examined the role of the substrate on electron-phonon coupling in normal-metal films of Mn-doped Al at temperatures below 1 K. Normal metal-insulator-superconductor junctions were used to measure the electron temperature in the films as a function of Joule heating power and phonon temperature. Theory suggests that the distribution of phonons available for interaction with electrons in metal films may depend on the acoustic properties of the substrate, namely, that the electron-phonon coupling constant Σ would be larger on the substrate with smaller sound speed.

Dipolar molecular rotors in the metal-organic framework crystal IRMOF-2.

Rotating polar linker groups in the cubic metal-organic framework single crystal known as IRMOF-2 were investigated for freedom of motion, response to an external electric field, and effects of dipole-dipole interactions. The crystals consist of octahedrally coordinated zinc oxide clusters linked by the bromoterephthalate group, which contains a rotatable bromo-p-phenylene moiety. We confirmed the rotation by dielectric spectroscopy and found a 7.