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Sergey Vitkalov
Professor
National Science Foundation Career Grantee
Division of Science
DepartmentMarshak 330

Profile
2012present Professor, Physics Department CCNY
20062012 Associate Professor, Physics Department, CCNY
20022006 Assistant Professor, Physics Department, CCNY
19982002 Research Professor, Research Foundation, CUNY
19971998 Research Associate, Chemistry Department, University of Florida
19891999 Senior Research Associate, P.N.Lebedev Physical Institute of Russian
Academy of Sciences, Russia
19861989 Research Associate, P.N.Lebedev Physical Institute of Russian
Academy of Sciences, Russia

Education
1986  Ph.D. at Institute of Solid State Physics of Russian Academy of Science.
Thesis: "Nonlinear microwave effects in Bismuth at high magnetic field"
Thesis advisers: V. F. Gantmakher and G. I. Leviev
1981  Master Degree at Moscow Institute of Physics and Technology
Physics 554

Courses Taught
2003 Spring: Science 10101 (Honors Center)
2003 Fall: Science and Technology in NYC (Honors College)
Photos: NAC building CCNY: #1, #2, #3, #4, #5, #6
Final Conference Fall2003; Graduate Center #1, #2, #3, #4, #5, #6, #7, #8
2004 Spring: Introductory Physics 207
2004 Fall: Introductory Physics 207 (Section MM2)
Photos: roomJ3 J417 J417 #2
2004 Fall: Science and Technology in NYC (Honors College)
Honors College Conference; December 2004 #1, #2, #3, #4, #5, #6, #7, #8
2005 Fall: Science and Technology in New York City (Honors College)
Photos: P1, P2, P3, P4, P5, P6
2005 Fall: Introductory Physics 207 (Section GH)
Photos: P1, P2, P3, P4, P5
2006 Fall: Introductory Physics 207 (Section GH)
Photos: P1, P2
2007 Spring: Introductory Physics 204
Photos: P1 P2 P3
2007 Fall: Introductory Physics 207 (Section GHGH2)
Photos: P1, P2
2008 Spring: Introductory Physics 208 (Section STST2)
Photos: P1, P2
2009 Fall: Introductory Physics 207 (Section GHGH4)
Photos: P1, P2, P3
2010 Spring: Science 10101 (Honors Program)
Presentations: Charging Hair, Physics of Dance (PD), PD2, PD3, PD4
Final Exam: P1, P2, P3, P4, P5, P6
Group Photos: P1, P2, P3
2010 Fall: Introductory Physics 207 ( Sections GHGH4)
Photos: P1, P2, P3, P4
2011 Fall: Introductory Physics 207 ( Sections GHGH5)
Photos: P1, P2, P32012 Fall:
Physics 207
Physics 554

Research Interests
Research is focused on dynamical and nonlinear properties of low dimensional
electron systems. Goals are to understand fundamental properties of electron
transport in nanoscaled objects.
RESEARCH
Nonlinear Properties of 2D electrons in crossed electric and magnetic field.
Two dimensional highly mobile electrons, placed in a quantizing magnetic field, demonstrate strong, severalfold reduction of resistance in response to dc electric field E. The nonlinearity is caused by a nontrivial, energy dependent heating, which occurs in systems with the quantized (discrete) spectrum. Our recent experiment indicates, that the dc driven heating occurs with no increase of a temperature or global broadening of the electron distribution. Instead there is strong overheating and overcooling of 2D electrons, which in the energy space occurs "locally", providing a stratification of the dc driven phase flow and leading the electron system into a state with a zero differential resistance. The peculiar heating results in an exceptionally strong violation of Ohm's Law, which is unusual for degenerate electrons. In addition, our results indicate that, in general, the effective overheating in the systems with discrete spectrum is significantly stronger than the one in systems with a continuous and homogeneous distribution of the energy levels.
Nonlinear response of low dimensional systems
Quantum dots:
Nonlinear directed transport in mesoscopic objects is a subject of considerable fundamental interest due to potential applications in nanoelectronics. An unavoidable break of the spatial inversion symmetry by impurity potential leads to photovoltaic effects in small quantum systems. More recently, various competing mechanisms of the photovoltaic effects and rectification in quantum dots have been proposed and investigated experimentally. Most efforts have been focused on the nonlinear properties of mesoscopic objects in the regime, where the electron transport is controlled by quantum interference. In our recent research we have studied the nonlinear electron transport in a different regime, where the classical ballistic trajectories appear to provide the dominant contribution to the nonlinearity. In magnetic fields we have observed a gigantic reduction of the directed electron transport through ballistic dot with lateral size, d = 1 micron, significantly smaller than the mean free path (8 micron) of the electrons in adjoining 2D layers.
Microthermocouple:
We have reported measurements of the rectification of microwave radiation (0.7–20 GHz) at the boundary between twodimensional electron systems, created by a narrow gap split gate on a silicon surface. We have studied the system of two metals; for different temperatures, electron densities, and microwave power. We have found that this tiny system of two different 2D metals work as a controllable microthermocouple. Microwaves heat the boundary between two dissimilar 2D metals, inducing a thermoelectric voltage. A comprehensive theory, calculating the voltage, is proposed. Excellent quantitative agreement is obtained between theory and experiment.

Publications
Scott Dietrich, Sergey Vitkalov, D. V. Dmitriev and A. A. Bykov Quantum lifetime of 2D electron in magnetic field, Physical Review B, 85, 115312 (2012).
CCNY Authors assigned: Scott Dietrich, Sergey Vitkalov
Scott Dietrich, Sean Byrnes, Sergey Vitkalov, D. V. Dmitriev and A. A. Bykov Quantum oscillations in crossed electric and magnetic fields, Physical Review B, 85, 155307 (2012).
CCNY Authors assigned: Scott Dietrich, Sean Byrnes, Sergey Vitkalov
D. V. Dmitriev, I. S. Strigin, A. A. Bykov, S. Dietrich, S. A. Vitkalov Transport scattering time and quantum lifetime of 2D electrons in GaAs/ AlAs heterojunctions, JETP Letters, 95, 467 (2012).
CCNY Authors assigned: S. Dietrich, S. A. Vitkalov
Bykov A. A., Goran A. V., Vitkalov S. A. Interference of magnetointersubband and phononinduced resistance oscillations in single GaAs quantum wells with two populated subbands, Physical Review B, 81, 155322 (2010).
CCNY Authors assigned: Vitkalov S. A.
Vitkalov S. A. Nonlinear Transport of 2D Electrons in Crossed Electric and Quantizing Magnetic Fields, Invited Talk,Bulletin of the American Physical Society, Volume 55, Number 2,http://meetings.aps.org/link/BAPS.2010.MAR.J2.3. (2010).
CCNY Authors assigned: Vitkalov S. A.
Vitkalov S. A., Goran A. V., Bykov A. A., Toropov A. I. Effect of electronelectron scattering on magnetointersubband resistance oscillations of two dimensional electrons in GaAs quantum well, Bulletin of the American Physical Society, http://meetings.aps.org/link/BAPS.2010.MAR.T25.6 (2010).
CCNY Authors assigned: Vitkalov S. A.
A. A. Bykov, E. G. Mozulev, S. A. Vitkalov Zero differential resistance in a double quantum well at high filling factors, Jetp Letters, 92, p.475 (2010).
CCNY Authors assigned: S. A. Vitkalov
A. V. Goran, A. A. Bykov, A. I. Toropov and S. A. Vitkalov Coexistence of two types of microwave induced resistance oscillations in 2D electron gas at large filling factors, Proceedings of 18th International Symposium: Nanostuctures; Physics and Technology", St. Petersburg Russia, p.73 (2010).
CCNY Authors assigned: S. A. Vitkalov
S. A. Vitkalov and A. A. Bykov Quantal heating in strong magnetic fields, Proceedings of 18th International Symposium: Nanostuctures; Physics and Technology", St. Petersburg Russia, 55 (2010).
CCNY Authors assigned: S. A. Vitkalov
Zhang Jing Qiao, Vitkalov Sergey, Bykov A. A. Nonlinear resistance of twodimensional electrons in crossed electric and magnetic fields, Physical Review B, 80, 045310 (2009).
CCNY Authors assigned: Vitkalov S. A. , Zhang Jing Qiao
Vitkalov S. A., Romero N., Bykov A. A. Warming in systems with discrete spectrum: spectral diffusion of two dimensional electrons in magnetic field, Bulletin of the American Physical Society, Volume 54, Number 1 (2009).
CCNY Authors assigned: Vitkalov S. A., Natalia Romero
Vitkalov Sergey Microwave rectification at a boundary between two twodimensional electron systems., Invited talk, State University of New York, Buffalo (2009).
CCNY Authors assigned: Vitkalov Sergey
Vitkalov S. A. Spectral diffusion of twodimensional electrons in crossed electric and quantized magnetic fields., Invited talk, National Research Council of Canada, Institute for Microstructu (2009).
CCNY Authors assigned: Vitkalov Sergey
Vitkalov Sergey Warming in systems with discrete spectrum, Invited talk, Symposium on Spin Physics and NanoMagnetism, CUNY 2009 (2009).
CCNY Authors assigned: Vitkalov Sergey
Goran A. V., Bykov A. A., Toropov A. I., Vitkalov S. A. Effect of electronelectron scattering on magnetointersubband resistance oscillations of twodimensional electrons in GaAs quantum wells, Physical Review B, 80, 193305 (2009).
CCNY Authors assigned: Vitkalov S. A.
Vitkalov S. A., Zhang Jin Qiao, Romero N., Bykov A. A. Nonlinear resistance of twodimensional electrons in crossed electric and quantized magnetic fields, Condensed Matter Seminar, The City College of New York, Physics Department (2009).
CCNY Authors assigned: Vitkalov S. A., Zhang Jin Qiao, Romero N.,
Vitkalov S. A. Nonlinear transport of 2D electrons in crossed electric and quantizing magnetic fields ( Review Article), International Journal of Modern Physics B, 23, 4727 (2009).
CCNY Authors assigned: Vitkalov S. A.
Natalia Romero , Sean McHugh , Myriam P. Sarachik , Sergey A. Vitkalov , A. A. Bykov Effect of parallel magnetic field on the zerodifferential resistance state, Bull. Am. Phys. Soc., http://meetings.aps.org/link/BAPS.2009.MAR.A31.5 (2009).
CCNY Authors assigned: Myriam P. Sarachik , Sergey A. Vitkalov
Jing Qiao Zhang, Sergey Vitkalov, A. A. Bykov, and A. I. Toropov Nonlinear transport of 2D electrons in magnetic fields, International Journal of Modern Physics B, v. 23, p.2689 (2009).
CCNY Authors assigned: Jing Qiao Zhang, Sergey Vitkalov
A. V. Goran, A. A. Bykov, A. I. Toropov and S. A. Vitkalov Effect of electronelectron scattering on magnetointersubband resistance oscillations of two dimensional electrons in GaAs quantum well, Physical Review B, 80, p.193305 (2009).
CCNY Authors assigned: S. A. Vitkalov
N. Romero, S. McHugh, M. P. Sarachik, S. A. Vitkalov, and A. A. Bykov Effect of parallel magnetic field on the zerodifferential resistance state, Physical Review B, 78, p. 153311 (2008).
CCNY Authors assigned: N. Romero, S. McHugh, M. P. Sarachik, S. A. Vitkalov
N. Romero Kalmanovitz, A. A. Bykov, Sergey Vitkalov, and A. I. Toropov Warming in systems with a discrete spectrum: Spectral diffusion of twodimensional electrons in a magnetic field, Physical Review B, 78, p. 085306 (2008).
CCNY Authors assigned: N. Romero Kalmanovitz, Sergey Vitkalov
N. Romero Kalmanovitz, I. Hoxha, Y. Jin, S. A. Vitkalov, M. P. Sarachik, Ivan A. Larkin, and T. M. Klapwijk Scaling of thermoelectric voltage induced by microwave radiation at the boundary between twodimensional electron systems, Physical Review B, 77, p.035415 (2008).
CCNY Authors assigned: N. Romero Kalmanovitz, I. Hoxha, Y. Jin, S. A. Vitkalov, M. P. Sarachik
N. Romero Kalmanovitz I. Hoxha Y. Jin S.A. Vitkalov M.P. Sarachik, I.A. Larkin, T.M. Klapwijk Scaling of thermoelectric voltage induced by microwave radiation at the boundary between twodimensional electron systems, Bulletin of American Physical Society, v. 53, N2, U37.00013 (2008).
CCNY Authors assigned: N. Romero Kalmanovitz I. Hoxha Y. Jin S.A. Vitkalov M.P. Sarachik
Sergey Vitkalov JingQiao Zhang, A. A. Bykov, A. K. Kalagin, A. K. Bakarov Zero differential resistance state in 2D dimensional electron system in strong magnetic field., Bulletin of American Physical Society, V53, N2, U37.00005 (2008).
CCNY Authors assigned: Sergey Vitkalov JingQiao Zhang
Sergey Vitkalov, JingQiao Zhang, Z. D. Kvon Directed electron transport through ballistic dot under microwave radiation, 29th International conference on the Physics of Semiconductors, Rio de Janeiro, Brazil (2008).
CCNY Authors assigned: Sergey Vitkalov, JingQiao Zhang,
SERGEY VITKALOV, JING QIAO ZHANG, A. A. BYKOV, A. I. TOROPOV Nonlinear transport of 2d electrons in magnetic field, 18th International Conference on High Magnetic Field, SanPaulo, Brazil (2008).
CCNY Authors assigned: SERGEY VITKALOV, JING QIAO ZHANG
Romero N., McHugh S., Sarachik M. P., Vitkalov S. A. and Bykov A. A. Effect of parallel magnetic field on the zerodifferential resistance state, March meeting of the American Physical Society, http://meetings.aps.org/link/BAPS.2008.MAR.A21.7 (2008)., A21.7. (2008).
CCNY Authors assigned: Sarachik M. P., Vitkalov S. A.
Kalmanovitz N. R., Hoxha I., Jin Y., Vitkalov S. A., Sarachik M. P., Larkin A. I. and Klapwijk T. M. Scaling of thermoelectric voltage induced by microwave radiation at the boundary between twodimensional electron systems, Physical Review B, 77, 035415 (2008).
CCNY Authors assigned: Vitkalov S. A., Sarachik M. P.
Romero N., McHugh S., Sarachik M. P., Vitkalov S. A., and Bykov A. A. Effect of parallel magnetic field on the zerodifferential resistance state, Physical Review B, 78, 153311 (2008).
CCNY Authors assigned: Sarachik M. P., Vitkalov S. A.
Bykov A. A., Zhang Jingqiao, Vitkalov Sergey, Kalagin A. K., Bakarov A. K. ZeroDifferential Resistance State of TwoDimensional Electron Systems in Strong Magnetic Fields, Physical Review Letters, 99, 116801 (2007).
CCNY Authors assigned: Vitkalov S. A.
Vitkalov Sergey Nonlinear resistive state of 2D electrons in magnetic fields, Invited talk, Condensed Matter Seminar, Brookhaven National Laboratory , December 2007 (2007).
CCNY Authors assigned: Vitkalov S. A.
Larkin A., Vitkalov S. A., Sarachik M. P. Rectification of Microwave Radiation at a Split Gate on a Silicon MOSFET, Brazilian Journal of Physics, (2007).
CCNY Authors assigned: Sarachik,Vitkalov
Zhang J.S., Bykov A. A., Kalagin A. K., Bakarov A. K. Effect of a dc electric field on the longitudinal resistance of twodimensional electrons in a magnetic field, Phys. Rev. B, Rapid Communications, 75, 081305 (2007).
CCNY Authors assigned: Zhang, Vitkalov
Bykov A. A., Marchishin I. V., Bakarov A. K., Zhang J., Vitkalov S. Hall Breakdown in Modulated Doped GaAs/AlAs heterostructure, JETP Letters, 85, 69 (2007).
CCNY Authors assigned: Zhang,Vitkalov
Zhang Jingqiao, Vitkalov Sergey, Kvon Z. D., Portal J. C., Wieck A. Directed Electron Transport through a Ballistic Quantum Dot under Microwave Radiation, Physical Review Letters, 97, 226807 (2006).
CCNY Authors assigned: Vitkalov S. A.
A. A. Bykov, Jingqiao Zhang, Sergey Vitkalov, A. K. Kalagin, and A. K. Bakarov Effect of dc and ac excitations on the longitudinal resistance of a twodimensional electron gas in highly doped GaAs quantum wells, Physical Review B, 72, 245307 (2005).
CCNY Authors assigned: Vitkalov