Controlled preparation of all high-Tc SNS-type edge junctions and DC SQUIDs

Gao, J.; Aarnink, W.A.M.; Gerritsma, G.J.; Rogalla, Horst

doi:10.1016/0921-4534(90)90464-p

Cited by 164 publications

(57 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…(PBCO) is a convenient semiconductor-like material which is isomorphic to the high-To superconductor (HTS) YBa2Cu3Ox (YBCO) and can be used as a barrier material. Our study of the YBCO/PBCO/YBCO multilayers and Josephson ramp junctions [10,[13][14][15] shows high quality crystal structures and interlayer boundaries as well as reproducible characteristics, including IcR, products up to 8 mV at 4.2 K, clear Josephson behavior and scaling of the junction parameters with the junction area. For better understanding of the Josephson effect in the YBCO/PBCO/YBCO ramp structures a more detailed study of the mechanisms of the current passage through this barrier layer is needed.…”

Section: Introductionmentioning

confidence: 99%

“…tures with a low ohmic noble metal [ 6,7 ], multilayer epitaxial structures [8][9][10], junctions with passivation of the YBa2Cu3Ox surface in a plasma [ 1 1 ] or with an N-YBCO layer deposited at low temperatures [ 12]. The Josephson coupling between the superconducting electrodes is established in different ways: through the high angle grain boundary, through the layer of low ohmic Ag or Ag/Au, high ohmic PrBa2CusOx or Nb-doped SrTiO3.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Transport processes in YBa2Cu3Ox/PrBa2Cu3Ox/YBa2Cu3Ox ramp type Josephson junctions

Boguslavskij

Gao

Rijnders

et al. 1992

Physica C: Superconductivity

Self Cite

View full text Add to dashboard Cite

A study of the YBCO/PBCO/YBCO ramp junctions with and without PBCO barrier shows that the Josephson and normal state behavior of these structures are determined by the thickness of the PBCO barrier and its nature. The boundary resistance and depression of the YBCO superconducting parameters near the interface do not strongly affect the junction characteristic. For thicknesses of 8 to 20 nm of the PBCO barrier the Josephson coupling is established through the high resistive barrier and the behavior of the junctions is better described by a SNINS model than by a SNS weak link model. Proximity effect, resonant tunneling and strong pair breaking mechanisms are discussed to explain the experimental characteristics. Good agreement with the experimental dependence of the IcR, product on the temperature and on the PBCO barrier thickness was obtained ifa strong pair breaking mechanisms in the barrier is taken into account.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Transport processes in YBa2Cu3Ox/PrBa2Cu3Ox/YBa2Cu3Ox ramp type Josephson junctions

Boguslavskij

Gao

Rijnders

et al. 1992

Physica C: Superconductivity

Self Cite

View full text Add to dashboard Cite

show abstract

“…Based on these epitaxially grown multilayers, all-high-To SNS-type Josephson junctions and DC SQUIDs have been successfully fabricated [ 2,3 ]. The composition of interfaces plays a very important role and strongly affects the performance of high-To superconducting devices.…”

Section: Introductionmentioning

confidence: 99%

Epitaxial multilayers of YBa2Cu3Ox/PrBa2Cu3Ox/YBa2Cu3Ox

Gao

Aarnink

Gerritsma

et al. 1991

Physica C: Superconductivity

Self Cite

View full text Add to dashboard Cite

Heteroepitaxial multilayers of YBa2Cu3OJPrBa2Cu3Ox/YBa2Cu30x have been made by sputtering. No degradation of the transition temperature and the critical current density due to the presence of the PrBa2Cu3Ox layer could be observed. By using high-resolution transmission electron microscopy the atomic details of the interfaces and the defect structures have been studied. These films showed a perfectly stacked lattice just above the interface between film and substrate. The orientation of the c-axis perpendicular to the substrate was fairly perfect. The structural faults are mainly distributed in the middle and overlying layers. The dominant defects in our films seems to be stacking faults which give rise to nano-sized coherent anti-phase domains with the 1-2-3 structure. Rutherford backscattering spectroscopy, secondary ion mass spectroscopy, and scanning Auger microscopy were used to examine the interdiffusion between layers. Within the experimental resolution of 7 nm no interdiffusion is visible between YBa2Cu3Ox and PrBa2Cu3Ox layers.

show abstract

“…1,[8][9][10] After deposition of an etch mask, e.g., photoresist or metal, the ramp is etched by an ion beam that strikes the sample at a certain angle. The angle of the ramp has to be well below 45…”

Section: Experimental Junction Fabricationmentioning

confidence: 99%

“…1 A-b-plane geometry allows for a wide range of coupling strengths between junction electrodes, from direct superconducting coupling over tunneling to insulation, depending on the height and thickness of a homoepitaxial barrier. In contrast, c-axis coupling is much weaker and in general Josephson currents cannot be observed.…”

Section: Introductionmentioning

confidence: 99%

The effect of ion milling on the morphology of ramp-type Josephson junctions

Blank

Rogalla

1997

J. Mater. Res.

View full text Add to dashboard Cite

Artificial barriers in Josephson junctions make it possible to change the height and width of the barrier independently. This technique can be realized in high-T c Josephson junctions using the ramp technique. In this article the fabrication of ramp-type junctions is discussed and the importance of the morphology of the ramp is pointed out. Detailed investigations are described which address the surface roughness and the damage due to ion-beam structuring of ramps. It is shown that hard masks can significantly improve the ramp quality by reducing the ion impact angle. Furthermore, annealing of the so structured ramps leads to unit cell steps enforcing a step-flow growth mode.

show abstract

Controlled preparation of all high-Tc SNS-type edge junctions and DC SQUIDs

Cited by 164 publications

References 9 publications

Transport processes in YBa2Cu3Ox/PrBa2Cu3Ox/YBa2Cu3Ox ramp type Josephson junctions

Transport processes in YBa2Cu3Ox/PrBa2Cu3Ox/YBa2Cu3Ox ramp type Josephson junctions

Epitaxial multilayers of YBa2Cu3Ox/PrBa2Cu3Ox/YBa2Cu3Ox

The effect of ion milling on the morphology of ramp-type Josephson junctions

Contact Info

Product

Resources

About