English
Related papers

Related papers: BCS Theory for Binary Systems with 2D Electrons

200 papers

The properties of the d-wave superconducting state in the two-dimensional system have been studied. It has been assumed, that the pairing mechanism is based on the electron-phonon and the electron-electron-phonon interactions. The obtained…

Superconductivity · Physics 2012-04-23 R. Szczȩśniak

The MgB$_2$ superconductor, discovered in 2001, has provided unique compound features of magnesium diboride with much higher critical temperature and critical field compared to NbTi superconductor. Its applications have been expanding owing…

Accelerator Physics · Physics 2022-02-18 Akira Yamamoto

The conductivity and permittivity optical spectra of iron-pnictide Ba(Fe0.9Co0.1)2As2 film (Tc=20 K) are analyzed. In the superconducting state, at all temperatures up to Tc the temperature dependences of the magnetic field penetration…

The BCS electron-phonon mechanism and the unconventional 'hole mechanism' have been proposed as explanations for the high temperature superconductivity observed in $MgB_2$. It is proposed that a critical test of which theory is correct is…

Superconductivity · Physics 2009-11-07 J. E. Hirsch , F. Marsiglio

First principles FLMTO-GGA electronic structure calculations of the new medium-$T_C$ superconductor (MTSC) $MgB_2$ and related diborides indicate that superconductivity in these compounds is related to the the existence of $p_{x,y}$-band…

Superconductivity · Physics 2009-11-07 N. I. Medvedeva , A. L. Ivanovskii , J. E. Medvedeva , A. J. Freeman

We present an investigation of the 2D attractive Hubbard model, considered as an effective model relevant to superconductivity in strongly interacting electron systems. We use both hybrid Monte Carlo simulations and existing hopping…

Strongly Correlated Electrons · Physics 2008-02-03 R. Lacaze , A. Morel , B. Petersson , J. Schroper

By investigating the bulk superconducting state via dc magnetization measurements, we have discovered a common resurgence of the superconductive transition temperatures (Tcs) of the monolayer Bi2Sr2CuO6+{\delta} (Bi2201) and bilayer…

Superconductivity · Physics 2019-01-30 Liangzi Deng , Yongping Zheng , Zheng Wu , Shuyuan Huyan , Hung-Cheng Wu , Yifan Nie , Kyeongjae Cho , Ching-Wu Chu

In this paper, we apply the two-band extension [1] of BCS theory [2] into the Mattis-Bardeen theory [3] to obtain the surface impedance of a two-band superconductor, and apply it to magnesium diboride (MgB2) for radiofrequency (RF)…

Superconductivity · Physics 2019-05-15 Binping Xiao , C. E. Reece

There is strong experimental evidence for pairing of polaronic carriers in the normal state, two distinct energy scales, d-wave superconducting order parameter,and charge segregation in the form of stripes in several cuprates.All these…

Superconductivity · Physics 2007-05-23 A. S. Alexandrov

A theory of fluctuations in two-band superconductor MgB$_{2}$ is developed. Since the standard Ginzburg-Landau (GL) approach fails in description of its properties, we generalize it basing on the microscopic theory of a two-band…

Superconductivity · Physics 2009-11-10 A. E. Koshelev , A. A. Varlamov , V. M. Vinokur

Boron in MgB_2 forms layers of honeycomb lattices with magnesium as a space filler. Band structure calculations indicate that Mg is substantially ionized, and the bands at the Fermi level derive mainly from B orbitals. Strong bonding with…

Superconductivity · Physics 2009-11-07 J. Kortus , I. I. Mazin , K. D. Belashchenko , V. P. Antropov , L. L. Boyer

Warming in complex physical systems, in particular global warming, attracts significant contemporary interest. It is essential, therefore, to understand basic physical mechanisms leading to overheating. It is well known that application of…

Mesoscale and Nanoscale Physics · Physics 2008-07-04 N. Romero Kalmanovitz , A. A. Bykov , S. A. Vitkalov , A. I. Toropov

With decreasing density $n_s$ the thermopower $S$ of a low-disorder 2D electron system in silicon is found to exhibit a sharp increase by more than an order of magnitude, tending to a divergence at a finite, disorder-independent density…

Strongly Correlated Electrons · Physics 2015-06-03 A. Mokashi , S. Li , Bo Wen , S. V. Kravchenko , A. A. Shashkin , V. T. Dolgopolov , M. P. Sarachik

Topological superconductivity can be engineered in semiconductors with strong spin-orbit interaction coupled to a superconductor. Experimental advances in this field have often been triggered by the development of new hybrid material…

We synthesized single crystalline and policrystalline MgB_2 under ambient pressures. The single crystals of MgB_2 were of good quality, where the crystal structure refinements were successfully converged with R = 0.020. The specific heat of…

Superconductivity · Physics 2009-11-07 Y. Machida , S. Sasaki , H. Fujii , M. Furuyama , I. Kakeya , K. Kadowaki

The complex conductivity of a MgB2 film has been investigated in the frequency range 4 cm^{-1}< nu < 30 cm^{-1} and for temperatures 2.7 K < T <300 K. The overall temperature dependence of both components of the complex conductivity is…

Superconductivity · Physics 2009-11-07 A. V. Pronin , A. Pimenov , A. Loidl , S. I. Krasnosvobodtsev

A method is presented for the unbiased numerical computation of two-particle response functions of correlated electron materials via a solution of the dynamical mean-field equations in the presence of a perturbing field. The power of the…

Strongly Correlated Electrons · Physics 2012-12-21 Nan Lin , Emanuel Gull , Andrew J. Millis

Due to the value of the isotope shift in sulfur hydrides, a phonon-mediated pairing scenario of superconductivity is generally accepted for these high-temperature superconductors which is consistent with the Bardeen-Cooper-Schrieffer (BCS)…

Superconductivity · Physics 2018-12-11 R. M. Méndez-Moreno

High-temperature superconductivity (HTS) of cuprates represents a challenge to the conventional theory. Here I review a multi-polaron approach to the problem based on our extension of the BCS theory to the strong-coupling regime. Since…

Superconductivity · Physics 2008-05-23 A. S. Alexandrov

We present an InAs-GaSb-based system in which the electric-field tunability of its 2D energy gap implies a transition towards a thermodynamically stable excitonic condensed phase. Detailed calculations show a 3 meV BCS-like gap appearing in…

Condensed Matter · Physics 2009-10-28 Y. Naveh , B. Laikhtman