NEEDLE-LIKE PROPERTIES OF THE PROBING RF FIELD OF “$MAGNETIC-FIELD$” PROBES BASED ON THE SINGLE-LAYER FLAT COILS

S.G. Gevorgyan; S.T. Muradyan; B.K. Kurghinyan; M.I. Qerobyan

doi:10.46991/PYSU:A/2011.45.3.047

Authors

S.G. Gevorgyan Superconductivity & Scientific Instrumentation Center, Chair of Solid State Physics, Faculty of Physics, YSU, Institute for Physical Research, National Academy of Sciences, Precision Sensors/Instrumentation Ltd., Armenia
S.T. Muradyan Superconductivity & Scientific Instrumentation Center, Chair of Solid State Physics, Faculty of Physics, YSU, Institute for Physical Research, National Academy of Sciences, Armenia
B.K. Kurghinyan Superconductivity & Scientific Instrumentation Center, Chair of Solid State Physics, Faculty of Physics, YSU, Armenia
M.I. Qerobyan Superconductivity & Scientific Instrumentation Center, Chair of Solid State Physics, Faculty of Physics, YSU, Armenia

DOI:

https://doi.org/10.46991/PYSU:A/2011.45.3.047

Keywords:

Single-layer Flat-Coil-Oscillator method, SFCO technique based “$magnetic-field$” probe, Fulde–Ferrel–Larkin–Ovchinnikov superconductivit, measurement technique for the searches of the nodal structure in FFLO-state

Abstract

A single-layer flat-coil-oscillator activated by a low power backward tunnel diode has been elaborated and created. As an inductance in a pick-up circuit of the oscillator, such a flat coil served as a “magnetic-field” probe in such a measuring instrument. The created oscillator was activated both without and with an external capacitance C₀ in its resonant circuit, i.e. the flat-coil oscillator might be also activated with its own (internal) capacitance C_c. Investigation of “probe-forma-tive” capabilities of this research instrument with such an unusual coil (versus C₀) showed that with a reduction of the value of this capacitance the feeling (probing) field of such a probe exponentially becomes longer, i.e. these probes become more far-ranging with decreasing C₀. The revealed property of “magnetic-field” probes would permit an essential widening of capabilities of flat-coil-based probe microscopes. It may also permit to enhance the efficiency of searching and detec-tion of the nodal structure, arising at an unusual phase transition from the “uni-form” to “non-uniform” superconductivity, predicted independently by Fulde and Ferrell, and Larkin and Ovchinnikov.