Phase locking in a multijunction superconducting loop

Abstract

Mutual phase locking of Josephson junctions in a multijunction superconducting loop (MSL) was investigated both theoretically and experimentally. The theoretical analysis predicts the existence of phase-locked states, where the circulating current in the loop serves for phase locking between junctions. The basic operating principles of a MSL were studied experimentally using high-TC bicrystal Josephson junctions. The enhancement of phase locking stability with respect to series arrays is reported.

Two-dimensional arrays of Josephson junctions in a magnetic field: A stability analysis of synchronized states

“…[1][2][3][4][5][6][7][8] Theoretical studies have begun to determine under what conditions and for what ranges of circuit parameters coherent emission should be possible from such arrays. [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] These arrays are also of interest as paradigms of nonlinear dynamical systems with many degrees of freedom. [24][25][26][27] Of particular interest have been the so-called phaselocked states of such arrays.…”

Spatially resolved detection of mutually locked Josephson junctions in arrays

“…Phase locking in arrays of Josephson junctions is of broad theoretical 1-5 and experimental [6][7][8][9][10][11][12][13][14][15] interest. From the application point of view the array state where all the junctions oscillate in-phase is the most desired one, because this in-phase state guarantees maximum microwave output power together with minimum linewidth.…”

Microscopics of fluctuations of the energy of atoms in solids

“…The MSL is the simplest structure where the mutual high-frequency interaction between junctions and their low-frequency interaction due to flux quantization in the superconducting loop can be observed at the same time. The MSL is important also from the point of view of applications, since the circuit based on MSL can be used as a tunable microwave oscillator [7] with robust stability in the presence of disorder [5], [8]. Recently, the experimental fabrication of MSL utilising high-T C technology, and its successful operation in wide range of temperatures and frequencies, has been demonstrated for small number of junctions in the loop [8], [9].…”

“…The MSL is important also from the point of view of applications, since the circuit based on MSL can be used as a tunable microwave oscillator [7] with robust stability in the presence of disorder [5], [8]. Recently, the experimental fabrication of MSL utilising high-T C technology, and its successful operation in wide range of temperatures and frequencies, has been demonstrated for small number of junctions in the loop [8], [9]. A structure similar to MSL can be created naturally or artificially in high-T C materials exhibiting intrinsic Josephson junctions [10].…”