Bilkent Magnetotransport & Spintronics Research Group

Tugrul Hakioglu

Department of Physics,
Bilkent University.

Phone (O): +90 (312) 290 2109
Phone (H): +90 (312) 290 4896
FAX: +90 (312) 266 4579

E-mail: hakioglu@fen.bilkent.edu.tr

Research

Bilkent Magnetotransport and Spintronics Group is currently interested in understanding nonlinear screening phenomenon in electron systems confined to two and one dimensions. The formations in the electron density of local areas of integer filling factor (incompressible regions) and their effect on th e charge transport are being examined. We are currently developing models for the local curent distribution in the compressible and incompressible regions. Incompresible regions geometrically follow the contours of the total electron potential of the confined 2DEG and for this reason there is sufficient reaso n to believe that they are the edge states that have been considered in the single particle Landauer-Buttiker formalism. New measurements using electronic Mach-Zender-Aharonov-Bohm Inteferometry has indicated a collective and phase coherent transport of electrons in t he incompressible regions. In order to explain the relevant measurements, the single particle Landauer-Buttiker picture must be abondened and a collective many particle microscopic formulation in the presence of a large number of electrons should be considered. To understand the "many-particle-phase-coherence " in the incompressible regions we are currently examining a spin-orbit coupling model generated by a strong perpendicular electric field. We believe that understanding the effect of the spin-orbit coupling on the "many-particle-phase-coherence" in the electron transport with the incompressible regions may sh ed light on the nature of the phase coherence observed in the Mach-Zehnder-Aharonov-Bohm experiments.

Teaching

Graduate courses:


  • Workshop on Field Theoretical Methods in Condensed Matter Physics-2006-Part I 15 January-3 February 2006 Feza-Gursey Institute/Istanbul:

    • the TUBITAK support is awarded for the organization of a national workshop on Mechanisms and Means of Decoherence and Dissipation in low dimensional Nanosystems

  • Workshop on Field Theoretical Methods in Condensed Matter Physics-2005-Part I 28 August-4 September 2005:

    • the support is awarded, the activity is yet to be held. This course is designed for the advanced research students working in the field of transport theory in low dimensional systems. It is a 2005 activity of the Research Education Program in Condensed Matter Physics. The concepts of self-consistent Thomas-Fermi-Schrodinger solutions for the charge distribution in 1-D heterojunctions and in disk-shaped semiconductor quantum dots are given. The course includes numerical calculations using self made basic routines to solve the Poisson-Schrodinger system in cylindrical geometry.

  • Workshop on Field Theoretical Methods in Condensed Matter Physics III 20 March-15 April 2005

    • This course is the third part of the National Research Education Program for the year 2005 in Condensed Matter Physics founded by myself. It is based on a collaborative group research in the field of Kondo Effect in Quantum Dots. The course 14 was taken by three selected students from the Part-II of the same course below and included 25 hours of teaching and research on Kondo effect in qdots. At the end of the semester, the students have reproduced the already known effect of Kondo type impurity scattering and reproduced the known spectral functions at the level of the well known text book by Gerald Mahan on Many Particle Physics For more information consult the web pge (in Turkish): http://www.fen.bilkent.edu.tr/~hakioglu/ymfec

  • Workshop on Field Theoretical Methods in Condensed Matter Physics II 31 August-10 September 2004

    • This course is the second part of the National Research Education Program for the year 2004 in Condensed Matter Physics mentioned above. The course was taught between August/23-September/10-2004 including 45 hour lecturing in a squeezed 3 week program of the selected national graduate students as well as faculty with research interests in Condensed Matter Physics. For more information on the program please visit http://www.fen.bilkent.edu.tr/~hakioglu/ymfec

  • Workshop on Field Theoretical Methods in Condensed Matter Physics I 1-23 July 2004

    • This course is the first part of the National Research Education Program for the year 2004 in Condensed Matter Physics founded by myself. The course was taught between July/1-July/23-2004 including 45 hour lecturing in a squeezed 3 week program of the selected national graduate students as well as faculty with research interests in Condensed Matter Physics. For more information on the program please visit http://www.fen.bilkent.edu.tr/~hakioglu/ymfec

  • Phys. 557 Special Topics in Mathematical Physics

    • Phase space approach to classical and quantum mechanics, theory of canonical transformations, canonical discretization of phase space, algebraic approach to quantum phase problem and quantum action angle operators, theory of generalized phase space distribution functions. Material: Own lecture notes; classic papers on the field.

  • PHYS 548 Advances in Condensed Matter Physics II

    • This course is given by three lecturers. In my part during the Fall 1998 semester I presented the continuous and discrete formulations of quantum phase space without subtle mathematical constructions of discrete and continuous group theory. A major part of the course was devoted to understanding the quantum phase problem and ways to solve it using discrete and semi-discrete phase space. Material: Lecture notes, historical papers by Dirac, von-Neumann, Schwinger, Moshinsky, Wolf etc. on canonical transformations and action-angle problem in quantum mechanics. Supplementary material in discrete mathematics was provided by, M. Artin (Algebra); S.R. Lang (Introduction to modular forms)

  • PHYS 553 Methods in Mathematical Physics

    • This course is designed to teach students the theory of special functions from the modern perspective of group theory representations. Emphasis is also given to elliptic functions and automorphic forms at the end of semester. Material: Arfken; Whittaker and Watson; Shoeneberg (Elliptic modular forms).

  • PHYS 551 Analytical Mechanics

    • Mechanics and variational calculus, static and dynamic equilibrium solutions of 15 mechanical systems, Dalembert, Lagrange and Hamilton's principles, Hamilton-Jacobi formalism and action-angle representations, symmetries and canonical transformations in phase space mechanics. Ideal fluid mechanics as a model for Liouville phase space. Material: Goldstein; independent lecture notes; L. Meirovitch (Methods of Analytical Dynamics); Chorin and Marsden (A mathematical introduction to fluid mechanics)

  • PHYS 548 Advances in Condensed Matter Physics II

    • (This course exposes the graduate students to advanced level special topics in Condensed Matter Physics given by three lecturers. The relevant section II is entitled as Introduction to Characterization and Generation of Chaos). Material: R.C. Hilborn (Chaos and non-linear dynamics: An introduction for scientists and engineers)


Undergraduate courses:


  • PHYS 405 Theory of Special Relativity (SR)

    • Experiments and introduction, postulates, gedanken experiments, Lorentz Trf., group properties, boost generators, Poincare group, relativistic kinematics, trf. btw. lab. and CM, Relativistic covariant E& M, trf. of fields, relativistic Thomas precession, relativistic mechanics, Lagrangian and Hamiltonian, Introduction to Classical Rel. Field theory, Noether's Theorem, energy momentum tensor, SR and Quantum Mech., Dirac's equation. Material: J.D. Jackson; H. Goldstein; J. Aharoni; H.M. Schwartz.

  • PHYS 205-206 Classical Mechanics

    • Standard and full coverage of J.B. Marion and S.T. Thornton's Classical Dynamics of Particles and Systems in two semesters.

  • PHYS 101-102 Fundamentals of Physics for Industrial Engineering

  • PHYS 102 Fundamentals of Physics for Computer Engineering

    • These two courses were designed for engineers and basically covered Holliday and Resnick in two semesters with more emphasis on mechanics and thermodynamics.

  • PHYS 449 Group Theory

    • group (G) axioms, exmpl's from simple finite dim. G's, multiplication tables, subG's, normal subG's, cosets, quotients. Transformations on and between G's: injection, surjection, bijection, homomorphism, isomorphism, automorphism, equivalence classes, Representations of G's, reps of simple Abelian G's, permutation G's, reducible, irreducible inequivalent reps, simple X-tallographic groups. Continuous groups, translation groups on the real line, on the circle, infinitesimal generators, representations, irreducibility of reps, angular momentum in two and three dim's. Material: Lecture Notes on Group Theory and Group Representations by L. Barker (Bilkent University Math. Dept.); own notes on discrete groups; M. Tinkham (Group Theory and Quantum Mechanics).

  • PHYS 243 Methods of Mathematical Physics

    • Linear Diff. Eq., Fourier and Laplace trf's, Frobenius Method and series 16 solutions, Bessel and Legendre functions, Sturm-Liouville Problem, Boundary Value Problems, Partial Diff. Eq., Special Topics in Math. Phys. (happens to be Green's function theory most of the time). Material: F.B. Hildebrand (Advanced Calculus for Applications); G. Arfken (Math. Methods for Physicists)

  • PHYS 256 Introduction Nuclear and Particle Physics

    • Quantum Statistics, Nuclear Models, Nuclear Decays and Reactions, Elementary Particles and Symmetries, Field Theory and Gauge Principle Material: R. Resnick and R. Eisberg ( second half of Quantum Physics of Atoms, Solids, Nuclei and Particles)

  • PHYS 453 Fundamentals of Nuclear and Particle Physics

    • Nuclear properties, phenomenological model, central forces, orbital ang. mom & spin, static electric and magnetic moments, nuclear decays, ?, ß, ? decays, Nuclear reactions & cross sections, Partial wave analysis, Resonances, Isospin and ? decay, Isospin and ? decay, Strangeness and weak decays Material: M.G. Bowler (Nuclear Physics)

  • PHYS 471 Advanced Computational Physics

    • In this senior course, students are given several different computational research papers. The prerequisites are Fortran 77 and Numerical methods for Physicists. They collaborate in writing the programs to repeat the numerical procedures needed in the paper of choice under the guidance of the professor. During the course, they learn how to use the numerical math. libraries as well as debugging methods. Usually, papers are selected from the current area of interests of the professor. For this reason, each year the course rotates among the faculty member. In my term the students worked in groups of two on the following papers:

    • Variational Study of a simple model for bipolarons, Phys. Rev. B45, 7102 (1992)
    • Two-site polaron problem: Electronic and Variational Properties, Phys. Rev. B45, 7730 (1992).
    • A Squeezed State Approach for the Large Polarons , J. Phys. Condens. Matter 5, 6729 (1993).
    • Variational ground state of a system with strong electron-phonon interaction, Phys. Rev. B 38, 11865 (1988).
    • Diffusion Limited Aggregation, Phys. Rev. B27, 5686 (1982).

Publications

  1. T. Hakioglu, "Yogun Madde Fiziginde Alan Kuramsal Kavramlar ve Yontemler (Eng:Field Theoretical Concepts and Methods in Condensed Matter Physics)" (language: Turkish, , in preparation, expected date of publication: August 2006)

  2. T. Hakioglu and A.S. Shumovsky, "Quantum Optics and Spectroscopy of Solids: Concepts and Advances" (Kluwer, Amsterdam, Jan. 1997) 248

  3. T. Hakioglu, "Spin-orbit coupling and complex electron-hole ordering", 2006, under preparation, ().

  4. §. Akta§, R.R. Gerhardts, A. Siddiki and T. Hakioglu, "Electric field profiles near the depleted regions in Hall bars with incompressible strips", under preparation, , ().

  5. T. Hakioglu, A. Tegmen and B. Demircioglu, "h-independent universality of the Quantum-Classical Canonical Transformations", 2006, submitted, Phys. Lett. A ().

  6. T. Hakioglu and M. §ahin, "Complex Excitonic Gap via Spin-Orbit coupling and BEC-BCS Crossover", 2006, submitted, Phys.Rev.Lett. ().

  7. C. Sanli, T. Hakioglu and I. Adagideli, "Fluctuation Dissipation Theorem for Spin and Spin Diffusion for Spin-Orbit-Environment Coupling", under preparation, , ().

  8. T. Hakioglu, "Short-time non Markovian Decoherence", submitted, J. Phys. A, (2006).

  9. T. Hakioglu, K. Savran, H. Sevincli and E. Me§e, "Non Markovian dehonerence: A ctitique of the two-level approximation", Journal of Magnetism and Magnetic Material, 300, e579 (2005).

  10. Kerim Savran, T. Hakioglu, E. Me§e and H. Sevingli, "The relevant time scale of decoherence is Gaussian: A critique of the Two-Level Approximation", J. Phys. C, 18, 345 (2006).

  11. T. Hakioglu and Kerim Savran, "The role of the environmental spectrum in the decoherence and dephasing of multilevel systems", Phys. Rev., B 71, 115115 (2005).

  12. T. Hakioglu, Kerim Savran and E. Me§e, "Questioning the validity of the two-level approximation", Proceedings of the Conference Macroscopic Quantum Coherence and Computing, Kluwer Publications, , (2004). Eds. P. Silvestrini, P. Delsing, C. Granata, Yu. Pashkin and B. Ruggiero

  13. I.O. Kulik , T. Hakioglu and A. Barone, "Quantum Computational Gates with Radiation Free Couplings", Europ. J. Phys., B 30, 219 (2002). also: [cond-mat/0203313]

  14. T. Hakioglu, J. Anderson, F. Wellstood, "Single and double bit quantum gates by manipulating degeneracy", Phys.Rev., B 66, 115324 (2002). also: [cond-mat/0109100]

  15. T. Hakioglu, "Nonlocal, noncommutative picture in quantum mechanics and distinguished canonical maps", Physica Scripta, 66, 345-353 (2002). [hep-th/0108125]

  16. T. Hakioglu and A. Dragt, "The Moyal-Lie theory of phase space quantum mechanics [quant-ph/0108081]", J. Phys., A, 6603 (2001).

  17. T. Hakioglu, "Extended covariance under nonlinear canonical transformations in Weyl quantization", ANL-HEP-PR-00-119, , [quant-ph/0011076] (2001). non-refereed

  18. T. Hakioglu, "The polar representation of the Wigner function and its applications in linear optics and engineering", Feature issue on phase space in optics, J. Opt. Soc. Am., A17, 2411 (Dec. 2000).

  19. T. Hakioglu and E. Tepedelenlioglu, "Action angle Wigner function: A discrete and algebraic phase space approach", J. Phys., A 33, 6357 (2000).

  20. T. Hakioglu and K.B. Wolf, "Canonical Kravchuk basis for discrete quantum mechanics", J. Phys., A 33, 3313 (2000).

  21. L. Barker, Q. Candan, T. Hakioglu, A. Kutay and H. Ozakta§, "The discrete harmonic oscillator, Harper's equation and the discrete fractional Fourier transform", J. Phys., A33, 2209 (2000).

  22. T. Hakioglu, V.A. Ivanov and M. Ye Zhuravlev, "SU(2)-path integral investigation of Holstein Dimer", Physica, A, 172 (2000).

  23. T. Hakioglu, "Linear canonical transformations and quantum phase: A unified canonical and algebraic approach", J. Phys., A32, 4111 (1999).

  24. V.A. Ivanov, M. Ye. Zhuravlev, V.S. Yarunin and T. Hakioglu, "Exactly soluble coherent state path integral with non-polynomial action", J. Phys., A32, L361 (1999).

  25. T. Hakioglu, "Operational Approach in the weak field measurement of polarization fluctuations", Phys. Rev., A 59, 1586 (1999).

  26. V.A. Ivanov, E.A. Ugolkova, M.Ye. Zhuravlev and T. Hakioglu, "Electronic Structure, Insulator-Metal Transition and Superconductivity in ? — ET2X Salts", Adv. Mater. Opt. Electron., 8, 53 (1998).

  27. T. Hakioglu and M. Ye. Zhuravlev, "Dynamical properties of the two dimensional Holstein-Hubbard model in the T = 0 normal state: A fluctuation based effective moment approach", Phys. Rev., B 58, 3777 (1998).

  28. T. Hakioglu, "Finite dimensional Schwinger basis, deformed symmetries, Wigner function and an algebraic approach to quantum phase", J. Phys., A 31, 6975 (1998).

  29. T. Hakioglu, "Admissible cyclic representations and an algebraic approach to quantum phase", J. Phys., A 31, 707 (1998).

  30. T. Hakioglu and H. Tureci, "Correlated Phonons and Tc dependent dynamical phonon anomalies", Phys. Rev., B 56, 11174 (1997).

  31. T. Hakioglu, M. Arik, "Quantum Stereographic Projection and the Homo-graphic Oscillator", Phys. Rev., A 54, 52 (1996).

  32. T. Hakioglu, V. A. Ivanov, "Isotope Effect in Borocarbides and Boronitrides", Doga Fizik/TUBITAK, 22, 863 (1998).

  33. T. Hakioglu, V.A. Ivanov, A.S. Shumovsky and B. Tanatar, "Phonon Squeezing via Correlations in the Superconducting Electron-Phonon Interaction", Phys. Rev., B 51, 15363 (1995).

  34. T. Hakioglu, V.A. Ivanov, A.S. Shumovsky and B. Tanatar, "Phonon Squeezing in the Superconductivity of Borocarbides", Physica, C 235-240, 2343 (1994).

  35. T. Hakioglu, V.A. Ivanov, A.S. Shumovsky and B. Tanatar, "Phonon Squeezing in Superconducting Borocarbides", Physica, C 234, 167 (1994).

  36. T. Hakioglu, A.S. Shumovsky and O. Aytur, "Operational Approach to Quantum Limits on Polarization Measurement", Phys. Lett., A 194, 304 (1994).

  37. B. Tanatar and T. Hakioglu, "Possibility of Superconductivity of two-dimensional Electrons on the Surface of Liquid Helium Films", Sol. State Comm., 88, 115 (1993).

  38. T. Hakioglu, "What can We Learn About Hadronic Intermittency by Studying Fractal Sets?", Phys. Rev, D 45, 3079 (1992).

  39. P. Carruthers and T. Hakioglu, "The Power Spectrum of Hadronic Rapidity Distributions", Phys. Rev., D 45, 4046 (1992).

  40. T. Hakioglu and M.D. Scadron, "Vector Meson Dominance, One Loop Quark Graphs and the Chiral Limit", Phys. Rev., D 43, 2439 (1991).

  41. T. Hakioglu and M.S. Scadron, "Field Theory Calculations of the Pion Mass at the One-Loop Level", Phys. Rev., D 42, 941 (1990).

  42. T. Hakioglu and M.D. Scadron, "Theory of Low Dimensional Peierls Transitions for Metal-Insulators and Superconductors", Re. of Sol. St. Sci., 1, 337 (1987).

  43. T. Hakioglu and K.B. Wolf, "Canonical Kravchuk basis for discrete quantum mechanics", in Developments of the mathematical ideas of Mykhailo Kravchuk, ed. by N. Virchenko, I. Katchanovski, V. Haidey, R. Andrushkiw and R. Voronka (Press of The National Technical University of Ukraine and Shevchenko Scientific Society (USA), 2004, New York, ) pp. 177-187.

  44. K. Savran and T. Hakioglu, "Environmental spectrum in decoherence and dephasing of realistic systems", in Proceedings of the International Symposium Mesoscopic Superconductivity and Spintronics: In the light of quantum computation, ed. by Hideaki Takayanagi (World Scientific Publishers, 2004, ) PP- •

  45. T. Hakioglu, "Interaction of two-level atomic system with a single-mode Radiation Field", in Proceedings of the Summer School on Quantum Optics and Spectroscopy of Solids, ed. by T. Hakioglu and A.S. Shumovsky (Kluwer Academic Publishers, January 1997, ) pp. 121-138.

  46. T. Hakioglu, V.A. Ivanov, A.S. Shumovsky and B. Tanatar, "Phonon Squeezing in Superconducting Borocarbides", in Proceedings of the International Conference on Materials and Mechanisms M2S — HTSC: High Temperature Superconductivity, Grenoble July 5-9 1994, ed. by P. Wyder (Elsevier, 1995, 1-5) pp.

  47. "T. Hakioglu", in Hadronic Intermittency and Correlation Distributions from a Chaotic Map, ed. by Proceedings of the Santa Fe Workshop (F. Cooper, R.C. Hwa and I. Sarcevic, World Scientific, Singapore) pp. March 1990. 353-361

  48. T. Hakioglu and M.D. Scadron, "Linear Sigma Model in One-Loop order", in Proceedings of the 25. International High Energy Physics Conference, ed. by (World Scientific, Singapore, 1990) pp. 775.

  49. T. Hakioglu and M.D. Scadron, "Theory of Low Dimensional Peierls Transitions for Metal-Insulators an Superconductors", in Proceedings of the Drexel International Conference on High Temperature Superconductivity, ed. by S.M. Bose and S.D. Tyagi (World Scientific, Singapore, 1987) pp. 191-196.

Talks and Presentations


Invited talks


  1. "Short time non Markovian Decoherence: Criticizing the Two-Level Approximation", Moscow International Symposium on Magnetism (MIS M) Dedicated to the 250 'th anniversary of the Lomonosov Moscow State University, Moscow State University/ Moscow/Russia, June 25-30 2005.

  2. "Non-perturbative ground state properties of the 2-D Holstein-Hubbard model", Andronikashvili School and Workshop on Modern Problems in Condensed Matter Physics, E. Andronikashvili Institute of Physics, Georgian academy of Sciences/Tbilisi/Georgia, 15 October-23 October 2000.

  3. "Five lectures on Continuous and discrete quantum phase space: A unified approach a la canonicality and covariance", Research semester on current problems in Quantum Field Theory, Feza Giirsey Institute, Kandilli, Istanbul, June 16-21 2000.

  4. "Quantum Mechanics on the discrete phase space ", Mathematical Physics IX, International Conference, Feza Giirsey Institute, Kandilli, Istanbul. Aug.9-15 1999

  5. "Wigner function in discrete quantum mechanics ", Optical systems in phase space and their Wigner functions, International Workshop, Centro Internacional de Ciencias/Universidad Nacional Autonoma de Mexico. July 1999

  6. "A Canonical and Algebraic Perspective into the Quantum Phase Space", Eskisehir Anadolu Univ., Workshop, 29 Oct. 1998.

  7. "Finite Dimensional Schwinger basis and algebraic quantum phase", Quantum Groups and contractions, International Workshop, Bogazigi Univ.. 14-17 Sept. 1997

  8. "Kaos ve Karma§iklikta Matematiksel Yontemler", Hacettepe Univ.Biyolojik Kaos, Panel Discussion, 17 Jan. 1997.

  9. "Phase Space Analysis of Interacting Systems, Wigner Function, Quantum State Tomography", Fizikte Geometri ve Topoloji Kis Okulu, Izzet Baysal Univ. Bolu and TUBITAK, 29 Ocak-2 §ubat 1996.

  10. "Quantum groups, Quantum Deformations and invertible non-linear maps", Group Theory in Physics: Barut Memorial, Conference, International Center for Physics and Applied Mathematics (ICPAM) Edirne. 21-27 Dec. 1995

  11. "Operational Quantum Limits on Polarization Measurement", Electron Theory and Quantum Electrodynamics, NATO-ASI, International Center for Physics and Applied Mathematics (ICPAM) Edirne, Turkey. January 1994

  12. "Phase in Quantized Angular Momentum Representation of the Free Electromagnetic Field", Frontiers in Mathematical Physics, International Center for Physics and Applied Mathematics (ICPAM) Edirne, Turkey, January 1994.

  13. "Quantized Phase States of SU(2)", 3rd. International Wigner Symposium, Oxford,England, September 1993.

  14. "Intermittency versus Non-Intermittency in High Energy Collisions", Workshop on Intermittency in High Energy Collisions, Center for Complexity, Santa Fe U.S.A.. April 1990

Other Talks and Presentations


  1. "Macroscopic Quantum Coherence, Groundstate degeneracy and Gauge Invari-ance", Istanbul Technical University, Dept. of Physics, 2 Nov. 2001,

  2. "."Phase space in Mechanics, Argonne National Laboratory, Argonne, IL 60439, USA, , 9 October 2000..

  3. "A canonical-Algebraic formulation of the quantum phase problem: A phase space approach", Feza Gu'rsey Institute/Istanbul, 25 March 1999,

  4. "."The Quantum Canonical Transformations and the quantum Phase: A canonical-algebraic approach, Math. Dept. Bilkent Univ., , 12 Nov. 1998.

  5. "The Quantum Phase: A dream of Dirac", Phys. Dept. Bilkent Univ., 14 Oct.1998,

  6. "."Quantum phase space, M.E.T.U., Physics Dept., , Dec. 10 1997.

  7. "Finite Dimensional Schwinger basis and algebraic quantum phase", M.E. T. U., Physics Dept., 15 Nov. 1998,

  8. "."The Homographic Oscillator and its cyclic representations, Physical Applications of Quantum Groups Winter School, , Izzet Baysal Univ.. Jan. 1997

  9. "Dynamical Effects of Low Temperature Anharmonicity in High Tc", Koq Univ., Istanbul, . April 1996

  10. "Phase Space Tomography in Fundamental Quantum Mechanics", Middle East Technical Univ., Ankara, . March 1996

  11. "Phase Probability Distributions in Weak Field Polarization Measurement", Rochester Conf. on Quantum Optics, Rochester, June 1995.

  12. "Homographic Oscillator Basis for Quantum Phase Problem", Rochester Conf. on Quantum Optics, Rochester, June 1995.

  13. "Operational Approach to Quantum Phase in Atom Field Interaction", Rochester Conf. on Quantum Optics, Rochester, June 1995.

  14. "Dynamical Phonon Corelations in Solids", TFD-15, Ka§, . Oct. 26-29, 1995

  15. "Phonon Squeezing in Conventional and High Temperature Superconductors I-II", Middle East Technical University, Ankara, October 1994.

  16. "Phonon Squeezing in Superconductivity", Istanbul Technical University, Istanbul, May. 1994

  17. "Properties of the Quantum Mechanical Phase in SU(2)", Bogaziqi University, Istanbul, December 1993.

  18. "Chaos and Complex Systems", Bilkent University Colloquium, Ankara, November 1993.

  19. "Wavelets:An Introduction", Bilkent University, Ankara, September 1992.

  20. "Wavelets and Their Importance in Physics", The University of Arizona, Tucson, AZ U.S.A., April 1992.

  21. "Long Range Behaviour of Hadronic Rapidity Correlations and Sum Rules", The University of Arizona, Tucson, AZ U.S.A., January 1991.

  22. "A Field Theory Model with Constraints:An Analogy to Polymers", The University of Arizona, Tucson, AZ U.S.A., November 1990.

  23. "Peierls Transitions and Low Dimensional Superconductivity", The University of Arizona, Tucson, AZ, U.S.A., May 1987.