Pulsed Laser Deposition Research Group
CNR-SPIN and University of Tor Vergata | Dipartimento di Ingegneria Civile e Ingegneria Informatica | Via Politecnico 1, I-00133 Roma
Scientific Popularizations:
Dr. Andrey Varlamov

Andrey Varlamov (AV)

BORN: April, 25, 1954 in Kiev, Ukraine (USSR).
Italy, Russian Federation
Since January, 2004, AV is Research Director (Dirigente di Ricerca) of the Institute for Superconductivity and Innovative Materials of the Italian National Research Council.

.- June 1977: BS and MS in Physics cum laude. Course of Moscow Physical-Technical Institute (1971—77), General and Applied Physics Department, Landau Institute Chair of Theoretical Physics.
.- Nov 1980: Ph.D. in Condensed Matter Theory, Postgraduate course at the Moscow Institute for Steel and Alloys (1977-1980), Title of the Thesis: “Kinetic phenomena in quasi-two-dimensional  superconducting systems”. Thesis Advisor: Professor A.A. Abrikosov.
.- Oct 1988: Doctor of Sciences (Habilitatus), Moscow Institute for Steel and Alloys, Title of the Thesis: “The kinetics and fluctuations in the vicinity of phase transitions in non-homogeneous electron systems”.
Languages: Russian (native), Ukrainian (native), English (fluently), Italian (fluently), French (can read and translate), Polish (can read and translate)

.- Nov 1999 – Dec 2003: Senior researcher, Italian National Institute for Physics of Matter, INFM-CNR
Permanent staff of the Moscow Institute for Steel and Alloys, Department for Theoretical Physics:
.- Oct 1990 – Aug 1999: Full Professor, Research Leader of the Laboratory of Superconductivity;
.- Jan 1987 - Sept 1990: Associated Professor;
.- Jul 1985 - Sept 1990: Senior Research Associate;
.- Mar  1981 - Jun 1985: Junior Research Associate.

Invited Scientist at INFM, Italy:
15/3/1994 - 15/3/1998; 15/3/1992 - 15/7/1992.

Invited fellow at the Condensed Matter Theory Group of Material Science Division of Argonne National Laboratory, USA, Dec 1992 - Dec 1993. One month visits: 2003, 2004, 2005, 2006, 2007, 2009, 2010, 2011.

Visiting Scientist at the International Center for Theoretical Physics, Trieste, Italy: Mar-Sept 1991.

Invited Professor at:
       University of Rome ''Tor Vergata'', Italy, 1996.
       Bordeaux University, France, 1997, 2000.
       Florence University, Italy, 1997, 1998.
       University of Minnesota, USA, 1999, 2000, 2001, 2002, 2003, 2005

Teaching Experience
.- 2004- current: Course (96 hours) in "Quantum Mechanics and Statistical Physics" for the master degree program “Math Engineering” in “Tor Vergata” University.
- Under-graduated and graduated courses in Quantum Mechanics, Statistical Physics, Theory of Superconductivity, Theory of Metals, Quantum Field Theory Methods in Statistical Physics at Moscow Institute for Steel and Alloys and other universities
.- Advisor of Ph.D. thesis: at Moscow Institute for Steel and Alloys (8 students), at Salerno University, Italy (1 student, coadviser), at Florence University, Italy (1 student, coadviser).
.- Adviser of MS thesis: at Moscow Institute for Steel and Alloys (15 students), at Florence University (student, coadviser), at Pavia University (2 students, coadviser), at Rome University La Sapienza (1 student, coadviser).
- In 2008 AV in collaboration with colleagues created the new master program “Nanometrology” based on Moscow Institute of Physics and Technology and Moscow Technological University.

.- First Prize at the International Students Olympiad in Physics, Bulgaria, 1971.
.- Leninski Komsomol Prize in Physics, USSR, 1986.
.- Member-correspondent of the Accademia di Scienze e Lettere “Brera”.
.- Doctor Philosophiae Honoris Causa of Bogolyubov Institute for Theoretical Physics (Ukraine), 2011.

.- Collaborative Research NATO GRANT # CRG 941187 Italy-USA (Principal Coordinator) 1995-1996.
.- Collaborative Research NATO GRANT # CRG 961187 Italy-USA (Principal Coordinator) 1997. 
.- Director of the NATO Advances Study Institute and Adriatico Research Conference
“Fluctuation Phenomena in Superconductors”, (International Center for Theoretical Physics, Trieste, Italy, 1996) (NATO Grant, 1996)
.- Research Projects # 18878 and # 20544 of Russian Foundation for the Fundamental Science (Principal Coordinator).
.- Research Grant # 1670 of INTAS (Coordinator from Russian side).
.- Collaborative Research NATO GRANT # CRG 978153, Italy-France-Russia, 2001-2002.
.- INFM PA 2002 “Transport and Interference in Nanostructures” (Principal Coordinator).
.- FIRB 2002 ''Transport  in Nanostructures''(Local Coordinator).
.- PRIN “Macroscopic Quantum Phenomena in Josephson Structures” coordinated by Prof. A. Barone (2006-2007).
.- PRIN “Superconductivity in Pnictides” local coordinator (2010).
.- Director of the ESF conference: “Nanoscience and Engineering in Superconductivity,  Hybrid and Josephson structures”, Anacapri, Italy, June, 2009.

During the period 1980-2010 AV has delivered more than 50 invited talks at different international congresses. List of invited talk during the last four years (2006-2010):
"Physics of Superconducting Phase Shift Devices", Ischia, 2005
MECO-30, Cortona, 2005.
Trends and Achievements in nanophysics, Minneapolis, USA, 2005
Science and Technology for the Industry of Tomorrow, Rome, Italy
6th SCENET School on "Superconducting Materials and Applications", Turku
SIF Conference, Catania, 2005.
V-th Fall Argonne Workshop in Nanoscience, Argonne USA, 2005.
Trends in Future Electronics, ESF, Bordeaux, 2006
Frontiers of Condensed Matter Theory,  USA, 2006
Classical Systems and Nanostructures, Dresden, Germany, 2006
Argonne Fall Workshop on Nanoscience, Argonne,  USA, 2006
Fundamental Problems of Mesoscopic Physics and Nanoelectronics, Mojacar, Spain, 2007
V.V.Shmidt Memorial Conference, Chernogolovka, 2007
Many-body theory of inhomogeneous superfluids, Pisa, Italy, 2007
Condensed Matter Theories 31, Bangkok, Thailand, 2007
I. Larkin Memorial Conference, Chernogolovka, Russia , 2007
Coherence and incoherence in strongly correlated systems, Rome, Italy, 2007,
Nanoscale Superconductivity and Magnetism,  Hsinchu, Taiwan , 2007
Annual Meeting of German Physical Society, Berlin, 2008
Fundamentals of Electronic Nanosystems, San Petersburg, 2008
Fundamental Problems of Superconductivity, Zvenigorod, 2008.
EUROFLUX2008: “Superconductivity: from study to applications”, Naples, 2008
“School of Nanophotonics and Photovoltaics”, Santiago de Cuba, January, 08-14 2009
ESF Conference: “Nanoscience and Engineering in Superconductivity, Hybrid and Josephson structures”, Italy, 2009.
ESF Conference: “Nanoscience and Engineering in Superconductivity, Hybrid and Josephson structures”, Italy, 2009.
5th International workshop on nanomagnetism & Superconductivity, Spain, 2009
ESF Conference: “Vortex matter in Nanostructured Superconductors”,
Rhodes, 2009
ESF International Workshop: Superconductivity in Reduced Dimensions” Salzburg, Austria, 2010.
Invited Colloquium Lecture “100 years of Supoerconductivity”  at Helsinki University;
Invited talk at the International Congress “Vortex XIII”, Chicago (USA);
Invited Lecture “100 years of Supoerconductivity” Annual Meeting of Italian Physical Society;
 Invited talk at March Meeting of the Mediterranean Institute of Fundamental Physics (Italy);
Invited talk at the International Conference “Complex Phenomena in superconductors & magnetic systems”, Bergen,(Norway);
Lectio Magistralis in Bogolyubov Institute for Theoretical Physics (Ucraine)  regarding the award of the degree “Doctor Philosophia Honoris Causa” (Ukraine);
Invited talk at the Workshop “New trends in the Theory of quantum Phase transitions”, Bordeaux, (France).

Invited seminars at Universities and Institutes:
Universities of Naples, Salerno, Messina, Roma I, Roma II, Genova, Pavia, Florence, Parma, Ancona, Camerino, Scuola Normale (Pisa) (Italy); Liege, Leuven (Belgium); CEA  Grenoble, Bordeaux, Paris (France); Lausanne, Neuchatel, Geneva, Zurich (Switzerland); Stuttgart, Munich, Bayreuth, Regensburg, Nurnberg, Karlsruhe (Germany); Leiden (Holland); Birmingham, Bristol, Cambridge University (UK); Stockholm, Goteborg (Sweden); Moscow State, Moscow Technological University, Landau Institute, FIAN, High Pressures Physics Institute, Kharkov, Kiev, Donetsk, Tbilisi (USSR); Argonne National Laboratory, Chicago, Northwestern, Massachusetts Institute of Technology , Stony Brook, Princeton, Los Angeles, Atlanta, Gainesville, Miami, Minnesota, University of Madison (USA); University of Oslo (Norway); Weizmann Institute (Israel), Vienne University (Austria).

Congresses organization (2006-2010)
.- Member of the Advisory Committee of the Advanced Research Workshops “Fundamentals of Electronic Nanosystems 2005” and “Fundamentals of Electronic Nanosystems 2006, 2008” (St. Petersburg, Russia).
.- Organizer of the International Workshop Science and Technology for the Industry of Tomorrow, Rome, Italy, 2007
.- Member of the Advisory Committee ,A.I.Larkin memorial conference, Chernogolovka, (Russia) 2006
.- Member of the Advisory Committee , Genova Festival of Science,  2003- current
.- Co-director, Italian-Russian Meetings in Theoretical Condensed Matter Physics, Rome, 2007, 2008, 2009, 2010
.- Director of the Meeting of Modern Science and School Physics: College for School Teachers of Physics in ICTP, Italy, April-May, 2011.

Other Scientific Activities:
.- Since Jan 1985: Member Of the Editorial Board of ''Kvant'', scientific -popularizing magazine of the Russian Academy of Sciences.
.- Nov 1986 - Mar 1992: Vice-Editor in Chief of ''Kvant'' magazine.
.- 1989-1992: Member of the Advisory Board of ''Quantum'' (Joint Soviet-American popular-science magazine for students).
.- 1987-1999: Member of the Scientific Council for Habilitatus Confirmation of Russian State Commission.
.- 2001-2003: Coordinator of the Solid State Physics Programs in ISI (Torino).

Referee of Physical Review B and Physical Review Letters; Soviet JETP and Letters, European Physical Journal and Europhysics Letters, Russian Foundation of the Fundamental Studies.

The fields where AV has been working during his research activity are:
.1. Theory of phase transitions. Fluctuation phenomena in superconductors. Theory of superconductivity: transport properties of superconductors, pseudo-gap-type phenomena.
.2. The role of interaction in the theory of disordered superconductors; metal-insulator transition; mesoscopic phenomena, nanophysics
.3. Metal theory; microscopic theory of electronic topological transitions (ETT); transport phenomena in quasi-crystals
.4. Heat transfer and thermoelectric power in interacting electron systems. Giant Nernst Effect in Superconductors
.5. Josephson junctions physics: fluctuations, macroscopic quantum tunneling in "finite size" junctions, superconducting detectors.
6. Graphene physics
.7. Non-local Ginzburg-Landau theory of superconductivity in multiband superconductors
resulting from the scientific activity of AV are:
- Number of papers in refereed journals: 160
- Number of communications to scientific meetings: more than 100
- Number of books:  10  (author), +3 (editor)
In the list of publications, the 30 most important papers on fluctuation phenomena in superconductors are reported
Details on the RESEARCH activity of AV are reported below.

.1. Theory of phase transitions. Fluctuation phenomena in superconductors. Theory of superconductivity: transport properties of superconductors pseudo-gap-type phenomena.
These are the fields where I have been working during all my scientific activity. I have studied the various fluctuation phenomena in superconducting systems, have extended the fluctuation theory beyond the limits of Ginzburg-Landau region accounting for the short wave and dynamical fluctuations, have discovered the DOS fluctuation contribution, important for many characteristics of superconductors. Special attention historically was devoted to the study of layered systems and various crossovers; the non-linear and non-local fluctuation phenomena were then investigated.
A wide range of experimental findings in the normal phase of well oxygenated HTS materials was explained basing on the approach formulated: the growth of the c-axis conductivity, the sign-changing magneto-conductivity, nuclear magnetic relaxation rate, tunneling anomalies, etc. These results found the wide resonance and were confirmed by the measurements of different groups from various countries.
The general concept concerning the role of inter-electron interaction in normal phase of HTS was presented in the review article. The model of c-axis transport based on the idea of Block oscillations in the narrow-band was proposed. I continue now the work on the explanation of the normal state anomalies of the underdoped HTS materials. The explanation of the various pseudogap-type phenomena in tunneling, ARPES, optical, resistive and NMR measurements was proposed on the basis of the unique concept of the special role of the inter-electron interaction in HTS materials. The manifestation of Thouless-Kosterlitz transition in HTS materials was studied in.
Recently I suggested to use  the `fluctuation spectroscopy' as a method to detect granularity in a disordered metal close to a superconducting transition. We showed that with lowering temperature T the resistance R(T) of a system of relatively large grains initially grows due to the fluctuation suppression of the one-electron tunneling but decreases with further lowering T due to the coherent charge transfer of the fluctuation Cooper pairs. Under certain conditions, such a maximum in R(T) turns out to be sensitive to weak magnetic fields due to a novel Maki-Thompson type mechanism.
On the basis of above results, I edited the book ''Fluctuation Phenomena in HTS materials", I am the author of the monograph ''Theory of Fluctuations in Superconductors'' (English version - Oxford University Press, 2005; Russian version - Russian Academy of Sciences, 2007)), and of the multi-authorial monograph ''Physics of Conventional and unconventional superconductors'' (Springer, 2002).

2. The role of interaction in the theory of disordered superconductors; metal-insulator transition; mesoscopic phenomena, nanophysics
In early 80-es I have studied the role of the particle-particle channel electron interaction on the properties of the disordered systems in the weak-localization regime. Later, the microscopic theory of the inter-electron interaction in disordered superconductors was proposed with its applications to the critical temperature and other thermodynamic characteristics renormalization and the effect on I-V characteristics of the Josephson junction with disordered electrodes. The theory of superconducting fluctuations at the edge of Anderson metal-insulator transition was developed in the frameworks of the self-consistent localization theory. Recently I have applied the ideas of the metal-insulator transition theory to the analysis of properties of the artificial infinite-layers superlattices. The exact solution for the fluctuation modes of the mesoscopic superconducting rings networks is found. The superconducting properties of nanotubes are studied. The theory of weak localization of granular metal is developed using the new diagrammatic technique in the reciprocal grain lattice representation. It is found that the properties of this correction are very similar to that one in disordered metal, with the replacement of the electron mean free path  by the grain diameter and the dimensionless conductance  by the tunnelling dimensionless conductance . In particular, we demonstrate that at zero temperature no conducting phase can exist for dimensions.  We also analyzed the WL correction to magnetoconductivity in the weak field limit.

3. Metal theory; microscopic theory of electronic topological transitions (ETT); transport phenomena in quasicrystals
During the period of 1985-1994 in the series of publications I have developed the microscopic theory of electronic topological transitions which explained the wide set of experimental results accumulated to this time. Two monographic review articles were published. I have predicted the giant Shubnikov-de-Haas type oscillations in the thermoelectric power of normal metal. The developed approach to multi-fractional Fermi surface systems has been served later as the basis for the formulation of the adequate model for the description of properties of MOSFET structures, electron transport in quasicrystals and now is used to describe the properties of the uderdoped phases of HTS, where the Van Hove similarities play the important role.

4. Heat transfer and thermoelectric power in interacting electron systems. Giant Nerst Effect in Superconductors
The problem of the heat transfer in interacting electron systems had been long discussed because of the poor definition of the notion ''heat'' in the Hamiltonian systems. I have proposed the approach based on the energy-momentum tensor treatment which permitted to carry out the specific diagrammatic technique for the heat transport vertices. This theory provided us the method to calculate the thermoelectric power, thermo-magnetic characteristics and heat conductivity in interacting electron systems.
Recently I developed the theory of the fluctuation-induced Nernst effect  for arbitrary magnetic fields perpendicular to the two-dimensional superconductor and temperatures beyond the upper critical field line in a two-dimensional superconductor. First, I derive a simple phenomenological formula for the Nernst coefficient, which naturally explains the giant Nernst signal due to fluctuating Cooper pairs. The latter is shown to be large even far from the transition and may exceed by orders of magnitude the Fermi liquid terms. It is argued that the magnitude and the behavior of the Nernst signal observed experimentally in disordered superconducting films can be well understood on the basis of superconducting fluctuation theory.

5. Josephson junctions physics: fluctuations, macroscopic quantum tunneling in "finite size" junctions, superconducting detectors.
I have studied the electrical-physical properties of different types of Josephson junctions in magnetic field, near electronic topological transition, near the superconducting transition temperature. The effect of the fluctuation pseudogap opening in tunneling I-V characteristic which is widely discussed nowadays was predicted by me in 1983 and measured in 1984 and 1986 on conventional junctions. Some specific nuclear particle detector idea was proposed on the basis of the SQUID combined with the superconducting granular media. I have proposed the theory of the pseudogap opening in high frequency conductivity measurements in HTS. The theoretical interpretation of the modulation measurements of YBCO optical reflectivity using a thermal wave technique was proposed.
The phenomenon of macroscopic quantum tunneling (MQT) in a finite size Josephson junction (JJ) with an externally applied magnetic field is studied. As it is well known, the problem of MQT in a point-like JJ is reduced to the study of the under-barrier motion of a quantum particle in the washboard potential. In the case of a finite size JJ placed in magnetic field, this problem is considerably more complex since, besides the phase, the potential itself, depends on space variables. We find the general expressions both for the crossover temperature between thermally activated and macroscopic quantum tunneling regimes and for the escape time. It turns out that in proximity of particular values of magnetic field the crossover temperature can vary non-monotonically.

6. Graphene physics
An analytic calculation of the conductivity of pure graphene as a function of frequency, wave-vector k, and temperature has been performed. Simple asymptotic expressions are given in various limiting cases. Our results are also used to explain the known dependence of the graphite conductivity on temperature and pressure.  Recently AV proposed the theory of giant oscillations of the Nernst coefficient in graphene and graphite.

7. Non-local Ginzburg-Landau theory of superconductivity in MgB2
A theory of fluctuations in two-band superconductor MgB2 has been developed. Since the standard Ginzburg-Landau  approach fails in description of its properties, we generalize it basing on the microscopic theory of a two-band superconductor. Calculating the microscopic fluctuation propagator, we build up the non-local two-band GL functional and the corresponding time-dependent GL equations. This allows us to calculate the main fluctuation observables such as fluctuation specific heat and conductivity.

8. Quantum Phase transitions. In collaboration with scientists of the Argonne National Laboratory AV developed a qualitative picture of the superconducting fluctuations close to the second critical field and at zero temperature , explaining the process of  Abrikosov lattice destruction.

AV has worked and plans to continue working both in the development of fundamental theories and their applications in the analysis of detailed experimental data.

  1. Alex Levchenko,  M. R. Norman, and A. A. Varlamov, PHYSICAL REVIEW B 83, 020506(R) (2011)
  2. M. Serbyn, M.Skvortsov, A.Varlamov, and V.Galitsky, PRL 106, 139702 (2011)
  3. A. Glatz, A. A. Varlamov and V. M. Vinokur EPL, 94 (2011) 47005
  4. Igor A. Luk’yanchuk,  Andrei A. Varlamov, and Alexey V. Kavokin, PRL 107, 016601 (2011)
  5. A. Glatz, A. A. Varlamov, and V. M. Vinokur, PHYSICAL REVIEW B 84, 104510 (2011)