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Aimed manipulation of fluxon dynamics in stacks of intrinsic Josephson-junctions out of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+x}; Gezielte Beeinflussung der Fluxondynamik in Stapeln intrinsischer Josephson-Kontakte aus Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+x}

Abstract

Goal of this thesis was to extend the knowledge of fluxon dynamics in intrinsic Josephson junctions out of BSCCO and to manipulate this dynamics in a purposeful way. New approaches to create ThZ-radiation were investigated. Step stacks out of BSCCO have been prepared with dimensions of 1-3 {mu}m (width) and 3-10 {mu}m (length). The necessary fabrication process was established based on Wang's double-sided technique. Transport measurements without and with magnetic field were realised on the so produced samples. The magnetic field of some Tesla was oriented parallel to the CuO{sub 2}-double layers. Collective plasma resonances were observed. Those were more stable than the resonances in mesa-structures. The resonances in the low current range can be assigned to an out-of-phase configuration, whereas in the high current range there are some possible configurations. Flux-flow-oscillations measured at these step stacks support the arrangement of the fluxons in an out-of-phase configuration. The in-phase configuration couldn't be observed clearly, so two approaches were followed to manipulate aimingly the fluxon dynamics to create THz-radiation: * control current * geometric manipulation: width-modulated stack For electronic manipulation an additional current line (control current line) was prepared along the stack's bottom. During transport measurements in zero field a current  More>>
Authors:
Publication Date:
Sep 29, 2007
Product Type:
Thesis/Dissertation
Report Number:
INIS-DE-0302
Resource Relation:
Other Information: TH: Diss. (Dr.rer.nat.)
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 36 MATERIALS SCIENCE; JOSEPHSON JUNCTIONS; MAGNETIC FIELDS; LAYERS; RESONANCE; MODULATION; COMPUTERIZED SIMULATION; DEPTH; BISMUTH COMPOUNDS; COPPER OXIDES; STRONTIUM COMPOUNDS; CALCIUM COMPOUNDS; HIGH-TC SUPERCONDUCTORS; QUASI PARTICLES; CUPRATES; PLASMA WAVES; MAGNETIC FLUX; TEMPERATURE RANGE 0000-0013 K; TEMPERATURE RANGE 0013-0065 K; FAR INFRARED RADIATION
OSTI ID:
20930639
Research Organizations:
Tuebingen Univ. (Germany). Fakultaet fuer Mathematik und Physik
Country of Origin:
Germany
Language:
German
Other Identifying Numbers:
TRN: DE07FB135
Availability:
Commercial reproduction prohibited; INIS; OSTI as DE20930639
Submitting Site:
DEN
Size:
133 pages
Announcement Date:
Sep 29, 2007

Citation Formats

Oehmichen, V. Aimed manipulation of fluxon dynamics in stacks of intrinsic Josephson-junctions out of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+x}; Gezielte Beeinflussung der Fluxondynamik in Stapeln intrinsischer Josephson-Kontakte aus Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+x}. Germany: N. p., 2007. Web.
Oehmichen, V. Aimed manipulation of fluxon dynamics in stacks of intrinsic Josephson-junctions out of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+x}; Gezielte Beeinflussung der Fluxondynamik in Stapeln intrinsischer Josephson-Kontakte aus Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+x}. Germany.
Oehmichen, V. 2007. "Aimed manipulation of fluxon dynamics in stacks of intrinsic Josephson-junctions out of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+x}; Gezielte Beeinflussung der Fluxondynamik in Stapeln intrinsischer Josephson-Kontakte aus Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+x}." Germany.
@misc{etde_20930639,
title = {Aimed manipulation of fluxon dynamics in stacks of intrinsic Josephson-junctions out of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+x}; Gezielte Beeinflussung der Fluxondynamik in Stapeln intrinsischer Josephson-Kontakte aus Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+x}}
author = {Oehmichen, V}
abstractNote = {Goal of this thesis was to extend the knowledge of fluxon dynamics in intrinsic Josephson junctions out of BSCCO and to manipulate this dynamics in a purposeful way. New approaches to create ThZ-radiation were investigated. Step stacks out of BSCCO have been prepared with dimensions of 1-3 {mu}m (width) and 3-10 {mu}m (length). The necessary fabrication process was established based on Wang's double-sided technique. Transport measurements without and with magnetic field were realised on the so produced samples. The magnetic field of some Tesla was oriented parallel to the CuO{sub 2}-double layers. Collective plasma resonances were observed. Those were more stable than the resonances in mesa-structures. The resonances in the low current range can be assigned to an out-of-phase configuration, whereas in the high current range there are some possible configurations. Flux-flow-oscillations measured at these step stacks support the arrangement of the fluxons in an out-of-phase configuration. The in-phase configuration couldn't be observed clearly, so two approaches were followed to manipulate aimingly the fluxon dynamics to create THz-radiation: * control current * geometric manipulation: width-modulated stack For electronic manipulation an additional current line (control current line) was prepared along the stack's bottom. During transport measurements in zero field a current of 0-30 {mu}A was sent through this control current line. The so created inhomogeneity should have provoked fluxons without the help of a magnetic field. A visible effect couldn't be measured. Geometric manipulation of fluxon dynamics to reach in-phase configuration relys on modulation of the stack's width: it has periodic necks (comb structure). First measurements on comb structures prepared in double-side technique show promising hints, that manipulation on purpose of fluxon dynamics is possible using width-modulation. Simulations were performed for different depths of modulation, small and large stacks at low and high external magnetic fields. For low magnetic fields and strong modulation depths a provocation of in-phase movement of the fluxons at the stack's end is seen. The fluxons reach the stack's end together. Aimed manipulation of fluxon dynamics is possible and promising using width-modulated stacks of intrinsic Josephson junctions. In prospective the parameter range should be investigated. (orig.)}
place = {Germany}
year = {2007}
month = {Sep}
}