CURRICULUM VITAE. 82 University Place, A522 Cook Fax: (802)

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1 CURRICULUM VITAE VALERI N. KOTOV February 2010 University of Vermont Tel.: (802) (office) Department of Physics Tel.: (617) (wireless) 82 University Place, A522 Cook Fax: (802) Burlington, Vermont Education 1996 Ph.D. in Physics, Clarkson University, Potsdam, NY, USA. Topic: Disordered Interacting Particle Systems, Advisor: G. Forgacs. M.S. in Physics (1993) 1990 M.S. in Theoretical Physics, Sofia University, Sofia, Bulgaria. (Nuclear and Elementary Particle Physics Specialization) Employment and Professional Experience Aug Assistant Professor, Department of Physics, University of Vermont, Burlington, VT Research Assistant Professor, Department of Physics & Department of Electrical and Computer Engineering Boston University, Boston, MA. Research Areas: Quantum Magnetism and Graphene Senior Assistant (with research and teaching duties), Institute of Theoretical Physics, Swiss Federal Institute of Technology (EPFL) & University of Lausanne, Lausanne, Switzerland. Teaching and Research in Condensed Matter Theory (Strongly Correlated Electron Systems) Research Associate, Department of Physics, University of Florida, Gainesville, FL. Research in Strongly Correlated Systems and Magnetic Materials Research Associate, School of Physics, University of New South Wales, Sydney, Australia. Research in Quantum Spin Systems and Frustrated Magnetism Graduate Teaching Assistant, Physics Department, Clarkson University. Undergraduate Physics Courses: Problem Sessions, Several Lectures Research Student, Department of Theoretical Physics, Sofia University, Sofia, Bulgaria. 1

2 Teaching Assistant for Undergraduate Mathematical Physics Course. Awards and Fellowships 1995 Outstanding Graduate Student Award, Clarkson University Research Fellowship, Department of Theoretical Physics, Sofia University Outstanding Student Award of the Bulgarian Ministry of Higher Education. Scientific Background Condensed Matter Theory and Quantum Many-Body Theory Main Areas of Research The Physics of Graphene: Electron Correlations, Impurity Effects. Quantum Magnetism: Dimerized Spin Systems, Frustrated Magnets, Novel Quantum Phases, Quantum Phase Transitions. Doped Quantum Antiferromagnets: Magnetic and Transport Properties of High-Temperature Cuprate Superconductors. Strongly Correlated Electronic Materials. Major Research Accomplishments Theory of Magnetic Moment Formation in Graphene (Anderson Impurity Model). Theory of Nonlinear Screening of Coulomb Impurities and Interaction Effects in the Polarization of Graphene. Graphene in Strong External Fields: Prediction of Coulomb Impurity Effects in Massive Graphene, Charging of the Vacuum and Nanoscale Charge Distribution. Theory of Incommensurate Magnetic Correlations and Transport in Underdoped High-T c Cuprate Superconductors. Theory of Exotic Weak Antiferromagnetic Order in Strongly Frustrated Spin Systems, such as Pyrochlore Magnets. Theory of Collective Excitations and Many-Body Effects in Low-Dimensional Quantum Antiferromagnets with Dimerization and Frustration. Accurate Description of Quantum Disordered (Dimerized) Phases and Quantum Phase Transitions in Antiferromagnets. Theoretical Modeling of Strongly Correlated Electronic Materials: Novel Molecular Magnets, Spin Dimer and Spin-Peierls Compounds, and Superconducting Oxides. 2

3 Teaching at the University of Vermont Electricity and Magnetism, PHYS 213, Fall 2009 Mechanics, PHYS 211, Spring 2010 Service at the University of Vermont Colloquium committee/dept. of Physics Graduate committee/dept. of Physics and Materials Science Program Organizer, Condensed Matter and Materials Physics Seminar/Dept. of Physics Teaching Experience (prior to UVM) Advanced Solid State Physics Course, covering Quantum Many-Body Physics University of Lausanne & Swiss Federal Institute of Technology (Lausanne) Academic Years (Assistant of Prof. F. Mila) Invited Lecturer, Graduate Series Field Theoretical Methods in Condensed Matter Physics on the Topic Low-Dimensional Quantum Spin Systems (6 Lectures), The University of New South Wales, Sydney, Fall Teaching Assistant for all Major Undergraduate Physics Courses at the Physics Department, Clarkson University, Potsdam, NY, Academic Years Teaching Assistant for Mathematical Physics Course, Department of Physics, Sofia University, Sofia (Bulgaria), Students Supervised: (1.)Diploma thesis work (after 4-th year) of A. Lüscher, 2003/defended Swiss Federal Institute of Technology, Lausanne (co-supervised with Prof. F. Mila) (2.)Ph.D. thesis work of P. Shevchenko, /defended The University of New South Wales, Sydney (co-supervised with Prof. O. Sushkov) (3.)Ph.D. thesis work of D.X. Yao, /defended Boston University, Boston, MA (co-supervised with Prof. D. Campbell) Professional Activities and Service Member, American Physical Society, European Physical Society. Visiting scholar at the Department of Physics, Yale University (Oct. Nov. 2000). Organizer, Condensed Matter Theory Journal Club, University of Florida, Spring/Fall Coordinator, Graphene Group Meeting, Boston University, Spring/Fall

4 Referee for Conference Proceedings: Highly Frustrated Magnetism 2003 (Grenoble), International Conference on Strongly Correlated Electron Systems, SCES2001 (Ann Arbor), SCES2007 (Houston), International Conference on Magnetism 97 (Cairns). Referee for the European Physical Journal B, Europhysics Letters, Physical Review Letters and Physical Review B. Languages English (fluent), Bulgarian (fluent), Russian (fluent), French (good). 4

5 Invited Talks and Lectures (19.) Graphene in a Strong Coulomb Field, Condensed Matter Theory Kids Seminar, Harvard University, April (18.) Exploring the New Physics of Graphene, Physics Colloquium, University of Vermont, Burlington, February (17.) Exploring the New Physics of Graphene, Physics Colloquium, University of North Dakota, Grand Forks, February (16.) Exploring the New Physics of Graphene, Physics Colloquium, University of Kentucky, Lexington, December (15.) Quantum Phase Transitions beyond the Dilute Bose Gas Limit, Condensed Matter Theory Seminar, Boston University, February (14.) Incommensurate Magnetism in Underdoped Cuprates, Colloquium, National Pulsed Magnetic Field Laboratory, Toulouse (France), December (13.) Exotic Order in Quantum Antiferromagnets, Theoretical Physics Seminar, LPTL, Université Pierre et Marie Curie, Paris (France), May (12.) Exotic Order in Quantum Antiferromagnets, Theoretical Physics Seminar, Université Paul Sabatier, Toulouse (France), March (11.) Dimerized Phases and Quantum Phase Transitions in Antiferromagnets, Colloquium, Institut Laue-Langevin (ILL), Grenoble (France), November (10.) Dimerized Phases in Quantum Antiferromagnets, Condensed Matter Seminar, Swiss Federal Institute of Technology (ETHZ), Zurich (Switzerland), November (9.) Universal Quantum Critical Scaling in Quantum Spin Ladder Systems, Condensed Matter Theory Seminar, University of Lausanne, Lausanne (Switzerland), Oct (8.) The Novel Quasi-One-Dimensional Spin Ladder Material (C 5 H 12 N 2 ) 2 CuBr 4 : Behavior in High Magnetic Field and Universal Quantum Critical Scaling, Condensed Matter Seminar, University of Florida, Gainesville, December (7.) Low-Energy Excitations and Spontaneous Dimer Order in the 2D J 1 J 2 Model, Invited Talk at the Institute for Theoretical Physics Conference on Quantum Magnetism, University of California, Santa Barbara, August (6.) Low-Energy Excitations and Dimer Order in the Two-Dimensional J 1 J 2 Model, Condensed Matter Theory Seminar, Yale University, New Haven, April (5.) Dimer Phases and Quantum Transitions in Low-Dimensional Antiferromagnets, Condensed Matter Seminar, University of Florida, Gainesville, February

6 (4.) Spin Liquids and Quantum Phase Transitions in Low-Dimensional Antiferromagnets, Theoretical Physics Seminar, The Australian National University, Canberra, May (3.) Low-Dimensional Quantum Spin Systems, Invited Series of Six Lectures for Postgraduate Students. Topics: Spin-Wave Theory of Low-Dimensional Antiferromagnets, Path Integral for Spin, Non-Linear Sigma Model, 2D Critical Behavior, Haldane s Conjecture, Spin Liquid States, The University of New South Wales, Sydney (Australia), Fall (2.) Non-Perturbative Methods in Disordered Interacting Systems, Theoretical Physics Seminar, The University of New South Wales, Sydney, October (1.) Instanton Approach to Interacting Random Systems, Theoretical Division (T-11) Seminar, Los Alamos National Laboratory, Los Alamos, Aug Conference Presentations (with Valeri Kotov as first author only) (25.) Polarization and Many-Body Phenomena in Massive Graphene, with V.M. Pereira, B. Uchoa, and A.H. Castro Neto, March Meeting of the American Physical Society, Pittsburgh, PA, (24.) Polarization and Many-Body Phenomena in Massive Graphene, with V.M. Pereira, B. Uchoa, and A.H. Castro Neto, Boston Area CarbOn Nanoscience (BACON) Day Conference, Boston University, June (23.) Coulomb Impurity Screening in Graphene, March Meeting of the American Physical Society, New Orleans, LA, (22.) Correlation Energy Effects in Graphene, with A.H. Castro Neto, March Meeting of the American Physical Society, Denver, CO, (21.) Are Stripes Generically Important for High-T c cuprates?, with A.H. Castro Neto and O.P. Sushkov, Gordon Research Conference on Correlated Electron Systems, Mount Holyoke, MA, June (20.) Transport Anisotropy due to Spiral Spin Order in Underdoped Cuprates, with O.P. Sushkov, March Meeting of the American Physical Society, Baltimore, MD, (19.) Spiral Spin Order and Transport Anisotropies in Underdoped Cuprates, International Workshop on Effective Models for Low-Dimensional Strongly Correlated Systems, Peyresq (France), September (18.) Quantum Phases in Frustrated Coupled-Tetrahedra Systems, with F. Mila and M.E. Zhitomirsky, Workshop on Materials with Novel Electronic Properties, Les Diablerets (Switzerland), September

7 (17.) Quantum Singlet Dynamics in Frustrated Coupled-Tetrahedra Systems, with M. Elhajal, M.E. Zhitomirsky, and F. Mila, International Conference on Highly Frustrated Magnetism (HFM2003), ILL Grenoble (France), August (16.) Quantum Singlet Dynamics in Frustrated Coupled-Tetrahedra Systems, Meeting on Oxides with Remarkable Properties, Caen-Colleville (France), May (15.) Spin-Peierls Transition in NaV 2 O 5 in High Magnetic Fields: Charge Fluctuation Effects, with S. Bompadre, A. Hebard, D. Hall, G. Maris, J. Baas, and T.T.M. Palstra, Condensed Matter Physics Conference (JMC8), Marseille-Luminy (France), August (14.) Competition between Valence Bond Liquid and Solid phases in the Kagome Antiferromagnet, with F. Mila, 19-th General Conference of the European Physical Society (Condensed Matter Division), Brighton (UK), April (13.) Spontaneously Dimerized Quantum Phases in Antiferromagnets, with W.H. Zheng, J. Oitmaa, and O.P. Sushkov, Swiss Physical Society Annual Meeting, EPFL, Lausanne (Switzerland), March (12.) The Kondo Lattice Model from strong-coupling viewpoint, with P.J. Hirschfeld, International Conference on Strongly Correlated Electron Systems (SCES2001), Ann Arbor, MI, August (11.) The Kondo Lattice Model from Local Viewpoint, with P.J. Hirschfeld, March Meeting of the American Physical Society, Seattle, WA, (10.) The Magnetic Spin Ladder (C 5 H 12 N 2 ) 2 CuBr 4 : High Field Magnetization and Scaling Near Quantum Criticality, with B.C. Watson, M.W. Meisel, D.W. Hall, G.E. Granroth, M.T. Montfrooij, S.E. Nagler, D.A. Jensen, R. Backov, M.A. Petruska, G.E. Fanucci, and D.R. Talham, Gordon Conference on Correlated Electron Systems, Plymouth, NH, June (9.) Critical Dynamics of Singlet Excitations in Frustrated Quantum Spin Systems, with M.E. Zhitomirsky and O.P. Sushkov, International Workshop on Latest Developments in Low-Density and Low-Dimensional Electron Systems (LD3), University of Florida, Gainesville, March (8.) Magnetic Bound States in the Spin Dimer Compound SrCu 2 (BO 3 ) 2, with S. Hershfield, March Meeting of the American Physical Society, Minneapolis, MN, (7.) Structure of the Spin-Liquid Phase of the J 1 J 2 Model, with W.H. Zheng, J. Oitmaa, and O.P. Sushkov, March Meeting of the American Physical Society, Atlanta, GA, (6.) Novel Approach to Description of Spin-Liquid States in Low-Dimensional Quantum Antiferromagnets, with W.H. Zheng, J. Oitmaa, and O.P. Sushkov, 7

8 March Meeting of the American Physical Society, Los Angeles, CA, (5.) Renormalization Group Approach to 1D Electron-Phonon Models, Statistical Mechanics Meeting 97, The University of New South Wales, Sydney (Australia), November (4.) Local Impurities in Two-Dimensional Quantum Antiferromagnets, with J. Oitmaa, and O.P. Sushkov, International Conference on Magnetism, Cairns (Australia), July (3.) Quantum Spin Ladders with Dimerization, with J. Oitmaa, Statistical Mechanics Meeting 96, University of Melbourne, Melbourne (Australia) (2.) Density of States of a Model Interacting Disordered System, with G. Forgacs, 72-nd Statistical Mechanics Meeting, Rutgers University, Piscataway, NJ, 1995 (1.) Density of States in Interacting Disordered Systems: an Instanton Approach, with G. Forgacs, Statistical Physics at the 45-th Parallel, Syracuse University, Syracuse, NY,

9 VALERI N. KOTOV Refereed Publications (Total citations = 647) 42. 1/N Expansion in Correlated Graphene, V.N. Kotov, B. Uchoa, and A.H. Castro Neto, Physical Review B 80, (2009). 41. Electron-Electron Interactions in Graphene: Current Status and Perspectives, V.N. Kotov, B. Uchoa, A.H. Castro Neto, and F. Guinea, Review Proposal for Reviews of Modern Physics (2008), accepted. Review Article commissioned by Reviews of Modern Physics, in preparation (editor code RW10019). 40. Weak Antiferromagnetic Order in Anisotropic Quantum Pyrochlores, V.N. Kotov, submitted to Physical Review B; arxiv: ; under revision. 39. Quantum Phase Transition in the Four-Spin Exchange Antiferromagnet, V.N. Kotov, D.X. Yao, A.H. Castro Neto, and D.K. Campbell, Physical Review B 80, (2009). 38. Adatoms in Graphene, A.H. Castro Neto, V.N. Kotov, J. Nilsson, V.M. Pereira, N.M.R. Peres, and B. Uchoa, for the Proceedings of the Graphene Week 2008, ICTP, Trieste, arxiv: Solid State Communications 149, 1094 (2009). 37. Polarization Charge Distribution in Gapped Graphene: Perturbation Theory and Exact Diagonalization Analysis, V.N. Kotov, V.M. Pereira, and B. Uchoa, Physical Review B 78, (2008). Selected for the Virtual Journal of Nanoscale Science & Technology (September 8, 2008). 36. Supercritical Coulomb Impurities in Gapped Graphene, V.M. Pereira, V.N. Kotov, and A.H. Castro Neto, Physical Review B 78, (2008). Selected for the Virtual Journal of Nanoscale Science & Technology (August 18, 2008). 35. Localized Magnetic States in Graphene, B. Uchoa, V.N. Kotov, N.M.R. Peres, and A.H. Castro Neto, Physical Review Letters 101, (2008). Selected for the Virtual Journal of Nanoscale Science & Technology (July 21, 2008). 34. Screening of Coulomb Impurities in Graphene, I.S. Terekhov, A.I. Milstein, V.N. Kotov, and O.P. Sushkov, Physical Review Letters 100, (2008). Selected for the Virtual Journal of Nanoscale Science & Technology (March 10, 2008). 33. Electron-Electron Interactions in the Vacuum Polarization of Graphene, V.N. Kotov, B. Uchoa, and A.H. Castro Neto, 1

10 Physical Review B 78, (2008). 32. AC Hopping Magnetotransport Across the Spin Flop Transition in Lightly Doped La 2 CuO 4, O.P. Sushkov and V.N. Kotov, Physical Review B 77, (2008). 31. Quantum Phase Transitions beyond the Dilute Bose Gas Limit, V.N. Kotov, D.X. Yao, A.H. Castro Neto, and D.K. Campbell, for Proceedings of SCES07, Houston, arxiv: Negative Hopping Magnetoresistance and Dimensional Crossover in Lightly Doped Cuprate Superconductors, V.N. Kotov, O.P. Sushkov, M.B. Silva Neto, L. Benfatto, and A.H. Castro Neto, Physical Review B 76, (2007). 29. Stability of the Spiral Phase and Superconductivity in the Two-Dimensional t-j model, O.P. Sushkov and V.N. Kotov, Journal of Physics and Chemistry of Solids 67, 99 (2006). 28. Spiral Spin Order and Transport Anisotropy in Underdoped Cuprates, V.N. Kotov and O.P. Sushkov, AIP Conference Proceedings 816, 112 (2006), arxiv:cond-mat/ Theory of Anisotropic Hopping Transpot due to Spiral Correlations in the Spin-Glass Phase of Underdoped Cuprates, V.N. Kotov and O.P. Sushkov, Physical Review B 72, (2005). 26. Dzyaloshinsky-Moriya Induced Order in the Spin-Liquid Phase of the Pyrochlore Antiferromagnet, V.N. Kotov, M. Elhajal, M.E. Zhitomirsky, and F. Mila, Physical Review B 72, (2005). 25. Theory of Incommensurate Magnetic Correlations across the Insulator-Superconductor Transition in underdoped La 2 x Sr x CuO 4, O.P. Sushkov and V.N. Kotov, Physical Review Letters 94, (2005). 24. Weak Antiferromagnetism and Dimer Order in Quantum Systems of Coupled Tetrahedra, V.N. Kotov, M.E. Zhitomirsky, M. Elhajal, and F. Mila, Physical Review B 70, (2004). 23. Stability of the Spiral Phase in the Two-Dimensional Extended t-j Model, V.N. Kotov and O.P. Sushkov, Physical Review B 70, (2004). 22. Soliton Binding and Low-lying Singlets in Frustrated odd-legged S=1/2 Spin Tubes, A. Lüscher, R.M. Noack, Gr. Misguich, V.N. Kotov, and F. Mila, Physical Review B 70, (R) (2004). 2

11 21. Superconducting Spiral Phase in the Two-Dimensional t-j Model, O.P. Sushkov and V.N. Kotov, Physical Review B 70, (2004). 20. Patterns of Symmetry Breaking in Systems of Coupled Tetrahedra, V.N. Kotov, M.E. Zhitomirsky, M. Elhajal, and F. Mila, Journal of Physics: Condensed Matter 16, S905 (2004). 19. The Kondo Lattice Model from Strong-Coupling Viewpoint, V.N. Kotov and P.J. Hirschfeld, Physica B 312, 174 (2002); arxiv:cond-mat/ The Magnetic Spin Ladder (C 5 H 12 N) 2 CuBr 4 : High Field Magnetization and Scaling Near Quantum Criticality, B.C. Watson, V.N. Kotov, M.W. Meisel, D.W. Hall, G.E. Granroth, M.T. Montfrooij, S.E. Nagler, D.A. Jensen, R. Backov, M.A. Petruska, G.E. Fanucci, and D.R. Talham, Physical Review Letters 86, 5168 (2001). 17. Critical Dynamics of Singlet Excitations in a Frustrated Spin System, V.N. Kotov, M.E. Zhitomirsky, and O.P. Sushkov, Physical Review B 63, (2001). 16. Collective Singlet Excitations and Evolution of Raman Spectral Weights in the 2D Spin Dimer Compound SrCu 2 (BO 3 ) 2, P. Lemmens, M. Grove, M. Fischer, G. Güntherodt, V.N. Kotov, H. Kageyama, K. Onizuka, and Y. Ueda, Physical Review Letters 85, 2605 (2000). 15. Spontaneous Dimer Order, Spectrum of Excitations, and Quantum Phase Transitions in the J 1 J 2 Heisenberg Model, V.N. Kotov, J. Oitmaa, O.P. Sushkov, and W.H. Zheng, Philosophical Magazine B 80, 1483 (2000). 14. Spin-Peierls Transition in NaV 2 O 5 in High Magnetic Fields, S.G. Bompadre, A.F. Hebard, V.N. Kotov, D. Hall, G. Maris, J. Baas, and T.T.M. Palstra, Physical Review B 61, R13321 (2000). 13. Nature of the Transition from the Spontaneously Dimerized to the Neel Phase in the Two- Dimensional J 1 J 2 Model, V.N. Kotov and O.P. Sushkov, Physical Review B 61, (2000). 12. Low-Energy Singlet and Triplet Excitations in the Spin-Liquid Phase of the Two-Dimensional J 1 J 2 Model, V.N. Kotov, J. Oitmaa, O.P. Sushkov, and W.H. Zheng, Physical Review B 60, (1999). 11. Spectrum of Elementary and Collective Excitations in the Dimerized S=1/2 Heisenberg Chain with Frustration, P.V. Shevchenko, V.N. Kotov, and O.P. Sushkov, Physical Review B 60, 3305 (1999). 3

12 10. Excitation Spectrum and Ground State Properties of the S=1/2 Heisenberg Ladder with Staggered Dimerization, V.N. Kotov, J. Oitmaa, and W.H. Zheng, Physical Review B 59, (1999). 9. Novel Approach to Description of Spin Liquid Phases in Low-Dimensional Quantum Antiferromagnets, O.P. Sushkov, V.N. Kotov, W.H. Zheng, and J. Oitmaa, Physica B 261, 1023 (1999). 8. Excitation Spectrum of the S=1/2 Spin Ladder with Frustration: Elementary Quasiparticles and Many-Particle Bound States, V.N. Kotov, O.P. Sushkov, and R. Eder, Physical Review B 59, 6266 (1999). 7. Bound States of Magnons in the S=1/2 Quantum Spin Ladder, O.P. Sushkov and V.N. Kotov, Physical Review Letters 81, 1941 (1998). 6. Magnetic Impurity in the Two-Dimensional Heisenberg Antiferromagnet, V.N. Kotov, J. Oitmaa, and O.P. Sushkov, Physical Review B 58, 8495 (1998). 5. Novel Approach to Description of Spin Liquid Phases in Low-Dimensional Quantum Antiferromagnets, V.N. Kotov, O.P. Sushkov, W.H. Zheng, and J. Oitmaa, Physical Review Letters 80, 5790 (1998). 4. Local Magnetic Impurities in the 2D Quantum Heisenberg Antiferromagnet, V.N. Kotov, J. Oitmaa, and O.P. Sushkov, Physical Review B 58, 8500 (1998). 3. Two-Chain Spin Ladder with Frustrating Second-Neighbor Interactions, W.H. Zheng, V. Kotov, and J. Oitmaa, Physical Review B 57, (1998). 2. Local Impurities in Two-Dimensional Quantum Antiferromagnets, V.N. Kotov, J. Oitmaa, and O.P. Sushkov, Journal of Magnetism and Magnetic Materials 177, 727 (1998). 1. The Lifshitz Tail in a Model of Interacting Particles, G. Forgacs and V. Kotov, Physical Review B 51, (1995). Thesis Work Ph.D. Thesis: The Instanton Method in the Theory of Disordered Interacting Particle Systems, Clarkson University (1996). M.S. Thesis: Electronic Spectrum of Quasicrystals with Impurities, Sofia University (1991), (in bulgarian). 4