High current gain HTS Josephson vortex flow transistors

Tavares, P.A.C.; Romans, E.J.; Pegrum, C.M.

doi:10.1109/77.783890

Cited by 5 publications

(3 citation statements)

References 12 publications

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“…Most of the subsequent work was based on bicrystal junctions. See, for example, Zhang et al (1994Zhang et al ( , 1995, Gerdemann et al (1995), Koelle et al (1995), Isaac et al (1997), Nguyen et al (1999), Tavares et al (1999).…”

Section: Three-terminal Devicesmentioning

confidence: 99%

Grain boundaries in high-Tcsuperconductors

2002

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Since the first days of high-T c superconductivity, the materials science and the physics of grain boundaries in superconducting compounds have developed into fascinating fields of research. Unique electronic properties, different from those of the grain boundaries in conventional metallic superconductors, have made grain boundaries formed by high-T c cuprates important tools for basic science. They are moreover a key issue for electronic and large-scale applications of high-T c superconductivity. The aim of this review is to give a summary of this broad and dynamic field. Starting with an introduction to grain boundaries and a discussion of the techniques established to prepare them individually and in a well-defined manner, the authors present their structure and transport properties. These provide the basis for a survey of the theoretical models developed to describe grain-boundary behavior. Following these discussions, the enormous impact of grain boundaries on fundamental studies is reviewed, as well as high-power and electronic device applications. CONTENTS I. Introduction 485 II. Introduction to Grain Boundaries 486 III. Preparation of Single Grain Boundaries 488 A. Bicrystalline junctions 489 B. Biepitaxial junctions 489 C. Step-edge junctions 491 IV. Structural Properties 491 V. Transport Properties of Grain Boundaries 496 A. Current-voltage characteristics 496 B. Critical current density 498 1. Dependence on grain-boundary angle 498 2. Temperature dependence of the critical currents 502 3. Magnetic-field dependence of the critical currents 502 C. Current-phase relation 504 D. Normal-state resistivity 504 E. The I c R n product 505 F. Grain-boundary capacitance 506 G. Microwave properties 507 H. Grain-boundary noise 507 I. Self-generated magnetic flux 509 J. Penetration of magnetic flux into grain boundaries 510 VI. Effects of Doping 510 VII. Grain-Boundary Mechanisms 511 A. Mechanisms based on structural properties 511 B. Mechanisms based on deviations from ideal stoichiometry 512 C. Order-parameter symmetry-based mechanisms 514 D. Interface charging and band bending 515 E. Mechanisms based on direct suppression of the pairing mechanism 516 VIII. Control of Grain Boundaries with Electric Fields or Quasiparticle Injection 517 A. Applied electric fields 517 B. Quasiparticle injection 518 IX. Irradiation of Grain Boundaries 518 A. Irradiation with electrons 518 B. Irradiation with light 518 C. Irradiation with ions 519 X. Bulk Applications 519 A. Powder-in-tube method 520 B. Coated conductors 520 XI. Applications of Grain Boundaries in Thin Films 522 A. SQUIDs 522 B. Radiation detectors and spectrometers 524 C. Three-terminal devices 525 D. Superconducting logic circuits 526 E. Research devices 526 XII. Summary and Outlook 528 Acknowledgments 529 References 529

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Section: Three-terminal Devicesmentioning

confidence: 99%

Grain boundaries in high-Tcsuperconductors

2002

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“…Therefore, g c and R m 1 are desired for a practical device. The HTS-JVFT has a better g c than the HTS-AVFT and has been demonstrated to have a g c > 20 [4][5][6]. However, the Josephson array in the HTS-JVFT requires a large device area with size up to ∼100 µm.…”

Section: Introductionmentioning

confidence: 99%

Flux transistor made from a single-layer niobium thin-film superconducting quantum interference device

Lam¹

2005

Supercond. Sci. Technol.

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A micrometre-size Josephson vortex flow transistor is demonstrated experimentally. The drain-source of this device is the output of a single-layer Nb superconducting quantum interference device (SQUID) with a nanometre-size hole, forming a nanoSQUID. The device input is a Nb strip, which is closely coupled to the nanoSQUID. The change of the input current induces a change in the magnetic flux coupling to the nanoSQUID, and hence modulates the current-voltage characteristics of the nanoSQUID. The current gain and transresistance of the device were investigated by evaluating the mutual coupling and the dynamic resistance of the nanoSQUID. A current gain of 0.3 and a transresistance >1 were achieved.

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“…The fabrication of an SFFT is simplest because it does not need multi-layer. The Josephson junction flux flow transistor with a multi-layer [11] is more complex and difficult to fabricate than SFFT. However, in the SFFT, it is difficult to fabricate the channel with sufficient reproducibility and controllability.…”

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confidence: 99%

Nano‐oxidation of superconducting flux flow transistor using a conductive atomic force microscope tip

Kang

Lim

et al. 2005

phys. stat. sol. (c)

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The atomic force microscopy (AFM) has exhibited its capability to fabricate the nano-scale electronic devices. We have fabricated superconducting flux flow transistors (SFFTs) in thin superconducting films by localized anodization using an AFM lithography method. The SFFT is composed of two strips, which is characterized as a transresistance device: one strip is as a source and drain terminal, the other is as a gate terminal. Generally, the channels of SFFT have been fabricated by chemical wet etching method and dry etching method. In this study we present a new fabrication of the SFFT with single or two channels using the artificial pattern formation method based on the AFM lithography. The critical current density in the fabricated SFFT with a multi-channel structure was decreased applying the current in the gate current line. From the measured results, it is shown that the critical current of an SFFT with two channels is larger than the critical current of single-channel due to the magnetic coupling between channels.

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High current gain HTS Josephson vortex flow transistors

Cited by 5 publications

References 12 publications

Grain boundaries in high-Tcsuperconductors

Grain boundaries in high-Tcsuperconductors

Flux transistor made from a single-layer niobium thin-film superconducting quantum interference device

Nano‐oxidation of superconducting flux flow transistor using a conductive atomic force microscope tip

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