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Certain high-Tc cuprate superconductors, which naturally realize a stack of Josephson junctions, thus can be used to generate electromagnetic waves in the terahertz region. A plate-like single crystal with 104 junctions without cavity resonance was proposed to achieve strong radiation. For this purpose, it is required to synchronize the Josephson plasma oscillation in all junctions. In this work, we propose to use two stacks of junctions shunted in parallel to achieve synchronization. The two stacks are mutually synchronized in the whole IV curve, and there is a phase shift between the plasma oscillation in the two stacks. The phase shift is nonzero when the number of junctions in different stacks is the same, while it can be arbitrary when the number of junctions is different. This phase shift can be tuned continuously by applying a magnetic field when all the junctions are connected by superconducting wires. [ABSTRACT FROM AUTHOR]

The discharge characteristics of radio frequency (rf) atmospheric-pressure glow discharges (APGDs, the relationship between the discharge mode after breakdown and the gap spacing are examined with pure argon and argon-ethanol mixture as the plasma-forming gas and using bare metal electrodes. The results have shown that the breakdown voltage is reduced when a small amount of ethanol is added into argon and a pure [alpha]-mode discharge is produced easily with the help of ethanol.

We study the dynamics of skyrmions in a metallic chiral magnet. First, we show that skyrmions can be created dynamically by destabilizing the ferromagnetic background state through a spin polarized current. We then treat skyrmions as rigid particles and derive the corresponding equation of motion. The dynamics of skyrmions is dominated by the Magnus force, which accounts for the weak pinning of skyrmions observed in experiments. Finally, we discuss the quantum motion of skyrmions. [ABSTRACT FROM AUTHOR]