Absolute measurement of penetration depth in a superconducting film by the two-coil technique

Wang, R. F.; Zhao, S. P.; Chen, G. H.; Qian-Sheng, Yang

doi:10.1063/1.125482

Cited by 11 publications

(13 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…12 It will therefore be interesting to test the microscopic theory using the experimental data, especially the low temperature data around and below T c,S Ј , which are previously not studied experimentally.…”

Section: Introductionmentioning

confidence: 99%

“…Since the two-coil technique requires a partial penetration of the magnetic field through the sample film, the film thickness should be limited in order to have a high accuracy in the measurements. 12 A second limitation for the samples comes from the theoretical side. Namely, one of the layers in an SSЈ sandwich should be thin compared to its coherence length so that the superconducting properties can be considered to be constant across the layer.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Magnetic penetration depth in Nb/Al and Nb/Cu superconducting proximity bilayers

et al. 2000

Self Cite

View full text Add to dashboard Cite

Magnetic penetration depth in Nb/Al and Nb/Cu superconducting bilayers, its absolute values and temperature dependencies under the variations of material and sample parameters are systematically investigated. Measurements of are performed by using the two-coil mutual inductance technique and the results are compared with a recent microscopic theory ͓Phys. Rev. B 59, 14 630 ͑1999͔͒ based upon Eilenberger-Usadel's quasiclassical equations of superconductivity. Our results show that the (T) characteristics at low temperatures usually follow a power law, or a linear temperature dependence, if the sublayer thicknesses are less than several times of their coherence length and the interface resistance is small. A two-gap, steplike feature in the (T) curve of the Nb/Al bilayer system will develop around the sublayer transition temperature of Al when the interface resistance increases or when the Al layer thickness becomes much larger than its coherence length. These results can be well described within the framework of the microscopic theory.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Magnetic penetration depth in Nb/Al and Nb/Cu superconducting proximity bilayers

et al. 2000

Self Cite

View full text Add to dashboard Cite

show abstract

“…1 and 2. The present method allows us to make these measurements on thin-film samples just a few micrometers across, whereas the techniques employed by Wang et al [3] and Gubin et al [9], in common with others, required samples at least 10 mm in diameter. …”

Section: Application Of Nanosquids To Noninvasive Measurement Ofmentioning

confidence: 99%

“…Niobium is chosen as the basis of our low-temperature superconducting devices because of its long-established use, conveniently adjustable transition temperature T c (4.2-9.4 K) [3], and the availability of suitable fabrication and clean-room facilities. Niobium films are deposited by dc magnetron sputtering from a 99.999% pure target onto oxidized silicon wafers or other suitable substrates (e.g., MgO and Al 2 O 3 ) held near room temperature in an ultrahigh-vacuum chamber with a base pressure around 10 −7 Pa. By controllably varying the film thickness from 14 to 200 nm, a range of T c from 5 to 9 K is achieved for the purposes of our experiment [4], [5].…”

Section: Film Deposition Device Fabrication and Testingmentioning

confidence: 99%

Novel Methods of Fabrication and Metrology of Superconducting NanoStructures

Líu

Macfarlane

Gallop

et al. 2007

IEEE Trans. Instrum. Meas.

View full text Add to dashboard Cite

Abstract-As metrology extends toward the nanoscale, a number of potential applications and new challenges arise. By combining photolithography with focused ion beam and/or electron beam methods, superconducting quantum interference devices (SQUIDs) with loop dimensions down to 200 nm and superconducting bridge dimensions of the order 80 nm have been produced. These SQUIDs have a range of potential applications. As an illustration, we describe a method for characterizing the effective area and the magnetic penetration depth of a structured superconducting thin film in the extreme limit, where the superconducting penetration depth λ is much greater than the film thickness and is comparable with the lateral dimensions of the device.

show abstract

“…In many practical situations, where the film thickness may be of the order 10 -20 nm, this condition prevails at temperatures between T c /2 and T c , where T c is the superconducting transition temperature. In published work, measurements of the penetration lengths in thin superconducting films have been based on the 2-coil method of Fiory et al [2] or variations thereof (eg Claassen et al [3]., Wang et al [4], ) where the lateral dimensions of the film are necessarily on the order of 10 mm due to the dimensions of practical wirewound coils. Other techniques based on measuring the change in resonant frequency of a microwave cavity, and on measuring the transmission of microwaves through the film, have also been recently described (Gubin et al, [5]).…”

Section: Introductionmentioning

confidence: 99%

Direct measurement of penetration length in ultrathin and/or mesoscopic superconducting structures

Líu

Macfarlane

Gallop

et al. 2006

Journal of Applied Physics

View full text Add to dashboard Cite

As the dimensions of thin superconducting structures become comparable with or less than the penetration length of magnetic flux into the structures, it becomes increasingly necessary to devise experimental tests of available theoretical models.One approach which we shall describe, enables penetration lengths to be derived from the measurement of the effective area of planar, thin-film structures with linear dimensions in the range 1 to 100µm. The effective area is defined by measurement of the inductive coupling of the structures to dc or low-frequency magnetic fields.The structures described consist of two parts: (1) An ultra-thin annular superconducting film with transition temperature T ca ("washer"); and (2) surrounding the washer is a superconducting ring with transition temperature T cs .Because the films are prepared in such a way that T ca < T cs , the ring-washer combination acts as a dc SQUID (Superconducting Quantum Interference Device) up to and beyond T ca , enabling the effective area of the washer to be measured over a wide temperature range. Results for the temperature dependence of the Pearl penetration length Λ(T), derived directly from measurements of the effective area, are compared both with theory and with other experimental data. Whereas alternative methods may be restricted to narrow-band, high-frequency fields and require sample dimensions of order 10 mm or greater, the method is inherently broad-band and is applicable to dimensions ≥ 1 µm.

show abstract

Absolute measurement of penetration depth in a superconducting film by the two-coil technique

Abstract: Articles you may be interested inModeling the nanoscale linear response of superconducting thin films measured by a scanning probe microwave microscope

Cited by 11 publications

References 12 publications

Magnetic penetration depth in Nb/Al and Nb/Cu superconducting proximity bilayers

Magnetic penetration depth in Nb/Al and Nb/Cu superconducting proximity bilayers

Novel Methods of Fabrication and Metrology of Superconducting NanoStructures

Direct measurement of penetration length in ultrathin and/or mesoscopic superconducting structures

Contact Info

Product

Resources

About