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Magnetic Radiospectroscopy Laboratory and | ||||||
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Title : Research Scientist
Phone : 007 8432 315116
Fax : 007 8432 387201
E-mail : Igor.Larionov@ksu.ru
Degree : PhD
Specialty: Condensed matter
Languages : English
Scientific field and main publications:
The first scientific paper was published during the 3-rd year undergraduate studentship (M.V.Eremin and I.A.Larionov, JETP Letters, 62, 203 (1995)). It was shown, that the BCS equation gives d-wave symmetry of superconducting gap in High Temperature Superconductors (HTSC), as was confirmed experimentally later, not s-wave, as was previously claimed. The type of this dependence is under great attention, since it is very important in connection with the mechanism of HTSC. The coexistence of d-wave superconductivity with sliding current structures, that are responsible, as assumed, for mysterious pseudogap properties with id-wave symmetry (id-CDW) was examined [ M.V.Eremin and I.A.Larionov, JETP Letters, 68, 611 (1998); also available at xxx.lanl.gov cond-mat - 0105136 ]. The theory predicted correctly the nontrivial peculiarities that were confirmed experimentally by Ekino et al., Phys. Rev B 60, 6916 (1999). Later, the id-wave scenario (also called D-Density Wave (DDW) or orbital antiferromagnetism) for pseudogap properties of HTSC was independently proposed and investigated by US scientists Ch.Nayak, D.Morr, S.Chakravarty and Nobel Prize winner R.B.Laughlin (Phys. Rev. B 64, 094503 (2001)), however, without numerical solution of integral equations.
Within the framework of the t-J model, a microscopical theory of the copper nuclear spin-lattice relaxation in the normal state of the HTSC La{2-x}Sr_xCuO4 and YBa2Cu3O{7-y} compounds was presented. The main contribution to the relaxation rate arises from strong short-range antiferromagnetic correlations between copper spins. The theory reproduced the doping and the temperature dependence of the copper relaxation rate as observed experimentally [A.Yu.Zavidonov, I.A.Larionov, and D.Brinkmann, Phys. Rev. B 61, 15462 (2000)]. The theory showed the connection between the phenomenological Nearly Antiferromagnetic Fermi Liquid (NAFL) description of HTSC [A.J.Millis, H.Monien, and D.Pines, Phys. Rev. B 42, 167 (1990)] and the microscopical t-J model, pointed by P.W.Anderson (Science 235, 1196 (1987)) as a perspective model to describe the electronic properties of layered HTSC cuprates.
Theory of the copper nuclear spin-lattice relaxation in the uniform state of the spin-Peierls compound CuGeO3 [A.Yu.Zavidonov, I.A.Larionov, and M.Itoh, Phys. Rev. B 61, 11625 (2000)].
The expression obtained for the superexchange coupling of magnetic ions and was used to analyse the isotope shifts of the Neel, superconducting, and pseudogap closure temperatures of layered cuprates [M.V.Eremin, I.M.Eremin, I.A.Larionov and A.V.Terzi, JETP Letters, 75, 395 (2002)].
Based on the susceptibility calculations the in-phase domain structure as a candidate for "stripe" picture was proposed. [I.A.Larionov and M.V.Eremin, J. of Supercond, 15 (2002) 389; J. Magn. Magn. Mater. 272-276, 181-182 (2004) ]. The electronic nature makes the x~1/8 conundrum common for layered copper oxide HTSC as was observed experimentally [M.Akoshima et al., Phys. Rev. B 57 (1998) 7491; W.L. Yang et al., Phys. Rev. B 62 (2000) 1361; I.Watanabe et al., Phys. Rev. B 62 (2000) 14524].
89Y NMR linewidth, Knight shift, spin-echo dephasing, and spin-lattice relaxation have been measured and analyzed in underdoped and overdoped Y1-xCaxBa2Cu3Oy samples [P.Carretta, A.Lascialfari, A.Rigamonti, P.Tedesco, F.Tedoldi, and I.A.Larionov, Phys. Rev. B 69, 104512 (2004)].
Using the Mori-Zwanzig projection operator procedure the relaxation function theory of doped two-dimensional S=1/2 Heisenberg AF system in the paramagnetic state is developed taking into account the hole subsystem as well as both the electron and AF correlations. The spin diffusion contribution to SLR is evaluated and is shown to play a significant role in HTSC compounds together with AF contribution. [I.A.Larionov, Phys.Rev.B 69, 214525 (2004)]. This theory has been used to give the analysis of dynamic spin susceptibility in terms of spin-wave-like excitations in underdoped layered copper oxides with implications for neutron resonance peak and $\omega$/T scaling from neutron scattering down to magnetic resonance experiments. The results suggest that the "pseudogap" effect seen with NMR in the high-Tc cuprates is hidden in the correlation length that affects the observable quantities [I.A.Larionov, Phys. Rev. B, 2005 accepted].
Professional career:
Graduated in 1992 from secondary school, Lyceum #1, and enrolled in Kazan State University.
Graduated with honours from Department of Theoretical Physics, Kazan State University in 1997.
George Soros Student Fellowship in 1995, 1996.
N.Lobachevsky award for students (1997).
In 1997-2000 Ph.D. student of Professor Mikhail V. Eremin, Department of Quantum Electronics & Radiospectroscopy, Kazan State University, Kazan, Russia
George Soros Ph.D. Student Fellowship in 1998, 1999.
In 1998-1999 academic year holder of grant of Russian Federation President fellowship program for education abroad - Ph. D. student (Doctorand) in Physik Institut, University of Zurich, Zurich, Switzerland, Group of Professor D.Brinkmann.
On 6-th July 2000 defended the Ph.D. thesis "Energy gap in HTSC versus wave vector, temperature and doping index" (in russian).
From 2000 - till present - Research Scientist in Magnetic Radiospectroscopy Laboratory of Kazan State University.
From 2000 - till present - researcher in Russian Scientific Council on Superconductivity Grant #98014-3.
E.K. Zavoysky award for young scientists (2001).
In 2002-2003 - responsible researcher in Russian Universities Grant #991327.
From 1.09.2003 - till present - holder of US CRDF - Russian Federation Ministry of Education fellowship for researchers with Ph.D. degree.
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