Mutual synchronization of two stacks of intrinsic Josephson junctions in cuprate superconductors

Abstract

Certain high-T c 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 10 4 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.

Chaos Synchronization Between Time Delay Coupled Josephson Junctions Governed by a Central Junction

“…It is well-known that Josephson junctions are a source of radiation with frequencies up to the terahertz (THz) region [17][18]. Terahertz waves have a wide range of possible uses, including security scanning, remote sensing chemical signatures of explosives, non-invasive applications in medicine [9].…”

“…One of the principal challenges in the field is to develop compact, low-cost, efficient THz sources. Additionally, for many remote sensing and imaging applications, high optical powers are desirable, in part owing to the significant attenuation of THz radiation by water vapor in the atmosphere [19,[17][18]. Unfortunately the radiation from a single Josephson junction is very weak, of the order of pW.…”

“…Unfortunately the radiation from a single Josephson junction is very weak, of the order of pW. Synchronization of arrays of Josephson junctions is one of the ways to increase the radiation power from such sources [17,[19][20]. Upon achieving synchronization the radiation power will be proportional to the number of Josephson junctions squared.…”

“…By synchronizing tens of thousands junctions radiation power as high as mW can be achieved. Recently it 1 was established that certain highly anisotropic cuprate superconductors naturally realize a stack of strongly electromagnetically coupled intrinsic Josephson junctions [17].…”

Chaos Synchronization Between Josephson Junctions Coupled with Time Delays

“…Upon achieving synchronization the radiation power will be proportional to the number of Josephson junctions squared. Recently it was established that certain highly anisotropic cuprate superconductors naturally realise a stack of strongly electromagnetically coupled intrinsic Josephson junctions [8]. From the fundamental point of view synchronization of huge number of complex systems could allow for higher efficiency of computational handling of such systems at least along the synchronization manifolds [1][2].…”