Polaron effects on superexchange interaction: Isotope shifts of T N , T c , and T* in layered copper oxides

Abstract

A compact expression has been obtained for the superexchange coupling of magnetic ions via intermediate anions with regard to polaron effects at both magnetic ions and intermediate anions. This expression is used to analyze the main features of the behavior of isotope shifts for temperatures of three types in layered cuprates: the Neel temperatures (TN ), critical temperatures of transitions to a superconducting state (TC), and characteristic temperatures of the pseudogap in the normal state (T * ).

Spin-Freezing Mechanism in Underdoped Superconducting Cuprates

“…[12] for details). It should be noted that the temperature dependence of Cu(2) Knight shift in YBa 2 Cu 4 O 8 , the evolution of the Fermi surface in Bi 2 Sr 2 CaCu 2 O 81y , and the k dependence of the pseudogap in the normal state have been successfully explained [13] in the framework of that model, including the d-wave orbital symmetry of the superconducting state (SC) [14]. The d-wave SC can coexist with extended charge density waves (for short id-CDW) as it was shown in previous works [15,16].…”

Estimation of the Forecast Hydrocarbon Resources of the North-Eastern Arctic Shelf of Russia

“…Prospective hydrocarbon resources of the Russian Arctic waters are shown in Table 3. The same authors in their work as an alternative assessment of prospective hydrocarbon resources of the Arctic seas of Russia cite the data of the USGS (2008) [4], which in comparison with the above volumes Kontorovich and others [7] differ in values many times less with respect to oil and gas and, as for condensate -on the contrary many times more.…”

“…The East Arctic OGBZ: oil (recovered) -6.0 billion tons, free gas -4.7 trillion m 3 ; Novosibirsk-Chukotka OGBZ: oil (recovered) -0.7 billion tons, free gas -1.1 trillion m 3 (table 2) [7]. To assess the resource base of oil and gas in the Arctic shelf of Russia, Eremin N.A., Kondratyuk A.T. and AN Eremin operate on the following indicators: the area of the shelf and continental slope of Russia -6.2 million km 2 ; a shelf with an area of at least 4 million km 2 , a continental slope and deepwater zones with an area of 0.4-0.5 million km 2 are promising for oil and gas, where 20 large offshore oil and gas provinces and basins have been identified, of which 10 are with proven oil and gas content [4].…”

“…The initial geological hydrocarbon resources on the Russian shelf, according to their estimates, amount to 136 billion tons of standard fuel, and the initial recoverable hydrocarbon resources reach 100 billion tons of standard fuel, including: 13 billion tons of oil and 87 trillion tons of oil equivalent. m 3 of gas [4]. The largest sedimentary basins in the Arctic part of Russia include: East Barents, South Kara, Laptev, East Siberian and Chukotka.…”

The enhanced s*-wave component of the superconducting gap in the overdoped HTSC cuprates with orthorhombic distortion

“…Theoretical considerations [51,52] also demonstrate admixing of s * -wave symmetry to the d-wave gap in the orthorhombic phase of cuprates. A large proportion of the s * -wave component was obtained in the work [52] within the t − J model but its concentration dependence is not discussed.…”