Type-I superconductor

About: Type-I superconductor is a research topic. Over the lifetime, 616 publications have been published within this topic receiving 7503 citations.

Low-Field Superconducting Spin Switch Based on a Superconductor / Ferromagnet Multilayer

Abstract: The principle of a novel device, which is called a superconducting spin switch or a spin valve for supercurrent, is proposed and theoretically justified. It is based on a four-layer antiferromagnet/ferromagnet/superconductor/ferromagnet spin-valve-like structure. Calculations show that this structure has either zero value or lower superconducting transition temperature for the parallel alignment of magnetizations in the ferromagnetic layers as compared with an antiparallel alignment of magnetizations. Thus, the supercurrent flowing through the superconducting layer can be switched by rotating the magnetization of the top free ferromagnetic layer by a weak external magnetic field.

A new heavy-fermion superconductor: UNi2Al3

Abstract: Measurements of the resistivity, susceptibility and specific heat are reported which clearly show that the hexagonal compound UNi2Al3 is a heavy-fermion magnet belowT N=4.6 K and a heavy-fermion superconductor belowT c=1 K.

Metallic ground state in an ion-gated two- dimensional superconductor

Abstract: A 3D approach to make 2D superconductors When the thickness of a superconducting film becomes comparable to the typical size of its electron pairs, its superconductivity enters a two-dimensional (2D) regime. Thinner films usually have higher amounts of disorder, making it difficult to isolate the 2D effects. To circumvent this limitation, Saito et al. induced charge carriers on the surface of the 3D insulator ZrNCl. This approach produced a clean superconducting layer thinner than the unit cell of the crystal. The superconducting state was extremely sensitive to the application of a perpendicular magnetic field, as expected for clean systems. Science, this issue p. 409 An electric-double-layer technique is used to induce clean two-dimensional superconductivity in the layered insulator ZrNCl. Recently emerging two-dimensional (2D) superconductors in atomically thin layers and at heterogeneous interfaces are attracting growing interest in condensed matter physics. Here, we report that an ion-gated zirconium nitride chloride surface, exhibiting a dome-shaped phase diagram with a maximum critical temperature of 14.8 kelvin, behaves as a superconductor persisting to the 2D limit. The superconducting thickness estimated from the upper critical fields is ≅ 1.8 nanometers, which is thinner than one unit-cell. The majority of the vortex phase diagram down to 2 kelvin is occupied by a metallic state with a finite resistance, owing to the quantum creep of vortices caused by extremely weak pinning and disorder. Our findings highlight the potential of electric-field–induced superconductivity, establishing a new platform for accessing quantum phases in clean 2D superconductors.

A new high- T c TlBa 2 Ca 3 Cu 4 O 11 superconductor with T c >120K

Abstract: Three superconducting compounds are known at present in the Tl–Ba–Ca–Cu–O system: Tl2Ba2CuO6+y, Tl2Ba2CaCu2O8+y, and Tl2Ba2Ca2Cu3O10+y, known by their cation numbers as '2201', '2212' and '2223', respectively1–3. The transition temperature Tc increases in this series, from 80 to 110 to 120 K, as the number of CuO2 layers in the unit cell increases from one to three. Here we report the synthesis and characterization of a new Tl–Ba-Ca–Cu–O superconductor which differs from these three in having only a single thallium layer (instead of two) per unit cell, but which has four CuO2 layers. The composition of the phase is TlBa2Ca3Cu4O11 (1234) and its structure is tetragonal, with lattice constants a = 3.85 A and c = 19.1 A.