Welcome to my little corner of the CSUSM website!

I am an experimental condensed matter physicist with primary interest in electronic conduction and magnetic phenomena in materials. My research interests span the areas of resistive random access memories, spin reorientation, nanoscience, and materials physics.

My teaching responsibilities include both lower and upper division physics courses. Those students pursuing a degree in the Biological Sciences or Biotechnology will likely see me in Physics 205 or 206. Applied Physics Majors will work on projects I designed in the Physics 380 Advanced Laboratory. I also routinely teach Physics 357 for Speech-Language Pathology Majors. The structure of our courses benefits greatly from the combined experimental backgrounds of our professors and also the physics education research actively pursued by the Department.

As for my extracurricular pursuits, I presently serve as a co-advisor to the CSUSM Chapter of Sigma Pi Sigma Physics Honor Society. I also perform scientific outreach (usually with a lot of liquid nitrogen!) and participate in various community engagement events.

Feel free to check out the tabs above to see a little more about what I do, or get in touch with me if there is anything that you would like to discuss.  You should check out the main Physics page for Departmental updates, internships information, and more!

Fellow educators in condensed matter physics may be interested in Advanced Laboratory projects provided by Quantum Design, Inc., at education.qdusa.com.

Ph.D. in Physics, University of Houston, 2008
Dissertation: "A carrier hopping mechanism for bipolar field induced resistive switching in metal-Pr0.7Ca0.3MnO3 interfaces"
Advisor, Professor Paul C.W. Chu 

M.S in Physics, University of Houston, 2004

B.S. in Physics with Honors, University of Houston, 2002
Honors Thesis: "Development of a straw tracking detector for a new muon to electron conversion experiment"
Advisor, Professor Ed V. Hungerford 

Projects have included:

• Magnetic spin reorientation phenomena in rare-earth orthoferrite systems
• Dielectric behavior in solid nanocomposite systems, which exhibit a negative capacitance phenomenon under application of high voltage bias
• New materials electrical transport characterization
• Resistive switching materials whereby the application of electric field induces a nonvolatile and reversible change in the crystalline structure, yielding a potential resistive random access memory

Any student who has an idea that they may want to pursue should feel free to talk to any of our faculty.

Refereed Publications (* denotes CSUSM undergraduate student)
“Utilizing Perylene in new organic donor-acceptor materials: highlighting the synthesis, structure, spectroscopy and physical properties of Perylene-pDNB and Perylene-TCNP,” D. Kimball*, R. Munns*, S. Fisher*, M. Bartolo*, J. Valdez*, S. Teat, S. Tsui, and E. Reinheimer, Journal of Chemical Crystallography 45, 169 (2015).

"Identification and analysis of a new organic donor–acceptor material: synthesis, structure, spectroscopy and transport properties of the 2:1 complex o-Me₂TTF–pDNB," S. Fisher*, S. Keene*, M. Bartolo*, S. Tsui, and E. Reinheimer, Journal of Chemical Crystallograhy 44, 261 (2014).

"Suppression of multi-level bipolar resistive switching in Ag/Pr_0.7Ca_0.3MnO₃ interfaces at low temperatures," S. Tsui, C. Salvo*, and M. Lopez*, Journal of Applied Physics 112, 114511 (2012).

"Don't erase that whiteboard! Archiving student work on a photo-sharing website," E. Price, S. Tsui, A. Hart*, and L. Saucedo*, The Physics Teacher 49, 426 (2011).

"Generation of negative capacitance in a nanocolloid," J. Shulman, Y.Y. Xue, S. Tsui, F. Chen, and C.W. Chu, Journal of Applied Physics 109, 034304 (2011).

"Interfacial resistive oxide switch induced by reversible modification of defect structures," S. Tsui, Y.Y. Xue, N. Das, Y.Q. Wang, and C.W.Chu, Physical Review B 80, 165415 (2009).

"General mechanism for negative capacitance phenomena," J. Shulman, Y.Y. Xue, S. Tsui, F. Chen, and C.W. Chu, Physical Review B 80, 134202 (2009).

"Kinetics and relaxation of electroresistance in transition metal oxides: model for resistive switching," N. Das, S. Tsui, Y.Y. Xue, Y.Q. Wang, and C.W. Chu, Physical Review B 80, 115411 (2009).

"Electric-field-induced submicrosecond resistive switching," N. Das, S. Tsui, Y.Y. Xue, Y.Q. Wang, and C.W. Chu, Physical Review B 78, 235418 (2008).

"Plasmalike negative capacitance in nanocolloids," J. Shulman, S. Tsui, F. Chen, Y.Y. Xue, and C.W. Chu, Applied Physics Letters 90, 32902 (2007).

"Mechanism and scalability in resistive switching of metal-Pr_0.7Ca_0.3MnO₃ interface," S. Tsui, Y.Q. Wang, Y.Y. Xue, and C.W. Chu, Applied Physics Letters 89, 123502 (2006).

"Field-induced giant static dielectric constant in nano-particle aggregates at room temperature," F.Chen, J. Shulman, S. Tsui, Y.Y. Xue, W. Wen, P.Sheng, and C.W. Chu, Philosophical Magazine 86, 2393 (2006).

"A negative dielectric constant in nano-particle materials under an electric field at very low frequencies," C.W. Chu, F. Chen, J. Shulman, S. Tsui, Y.Y. Xue, W. Wen, and P. Sheng, Proceedings of the SPIE 5932, 139 (2005).

"Field-induced resistive switching in metal-oxide interfaces," S. Tsui, A. Baikalov, J. Cmaidalka, Y.Y. Sun, Y.Q. Wang, Y.Y. Xue, C.W. Chu, L. Chen, and A.J. Jacobson, Applied Physics Letters 85, 317 (2004).

"Field-driven hysteretic and reversible resistive switch at the Ag-Pr_0.7Ca_0.3MnO₃ interface," A. Baikalov, Y.Q. Wang, B. Shen, B. Lorenz, S. Tsui, Y.Y. Sun, Y.Y. Xue, and C.W. Chu, Applied Physics Letters 83, 957 (2003).

"Crypto-superconductivity in RuSr₂GdCu₂O₈," Y.Y. Xue, S. Tsui, J. Cmaidalka, R.L. Meng, B. Lorenz, and C.W. Chu, Physica C: Superconductivity 341-348, 483 (2000).

"A possible crypto-superconducting structure in a superconducting ferromagnet," C.W. Chu, Y.Y. Xue, S. Tsui, J. Cmaidalka, A.K. Heilman, B. Lorenz, and R.L. Meng, Physica C: Superconductivity 335, 231 (2000).

Curriculum (* denotes CSUSM undergraduate student)
“Heat capacity of Fe3O4 (Magnetite),” S. Tsui, S. Sherman*, and R. Averitt, Quantum Design Education Module for advanced laboratory instruction, 2020. https://education.qdusa.com/experiment12.html

“Doping-dependent spin reorientation phenomenon in holmium-based orthoferrite,” J. Gregorio* and S. Tsui, Quantum Design Education Module for advanced laboratory instruction, 2017. https://education.qdusa.com/experiment10.html

“Fe₃O₄ magnetic characterization,” S. Tsui and J. Tally*, Quantum Design Education Module for advanced laboratory instruction, 2016. http://education.qdusa.com/experiment9.html

“YBCO magnetic characterization,” S. Tsui, Quantum Design Education Module for advanced laboratory instruction, 2016. http://education.qdusa.com/experiment8.html

“Magnetic demonstrations: magnetic signatures of some common states of materials,” S. Tsui and N. Dilley, Quantum Design Education Module for advanced laboratory instruction, 2015. http://education.qdusa.com/experiment7.html

“YBCO synthesis and characterization,” S. Tsui, Quantum Design Education Module for advanced laboratory instruction, 2015. http://education.qdusa.com/experiment5.html

“Heat capacity of vanadium oxide,” R. Averitt and S. Tsui, Quantum Design Education Module for advanced laboratory instruction, 2015. http://education.qdusa.com/experiment3.html

Physics 201: Physics of Mechanics and Sound

First semester introductory course for physical science and math students with calculus I.

Physics 202: Physics of Electricity and Magnetism

Second semester introductory course for physical science and math students with calculus II.

Physics 203: Modern Physics

This is the third semester of our introductory physics sequence for physical science and math students with calculus. Topics include thermodynamics and quantum physics.

Physics 101: Introduction to Physics I

First semester introductory course for students without calculus.

Physics 205: Physics for the Biological Sciences I

First semester introductory course for students majoring in biotechnology and biological sciences. This course is taught in an inquiry-based learning format and requires calculus I.

Physics 206: Physics for the Biological Sciences II

Second semester introductory course for students majoring in biotechnology and biological sciences. This course is taught in an inquiry-based learning format and requires calculus I.

Physics 357: The Science of Speech and Hearing

Introduction to wave phenomena, especially as they relate to speech and hearing. This general education course is part of the Speech-Language Pathology curriculum.

Physics 380: Advanced Laboratory

Applied Physics students practice experimental techniques with various projects, data analysis, and scientific writing.

Physics 422: Applied Solid State Physics

This course covers topics including crystal structure, elementary band theory, semiconductors, magnetism, and solid state devices.

Physics 499: Senior Laboratory Thesis

Independent undergraduate research units for Applied Physics majors. Enroll by contacting individual faculty members.

Chair, 2019-2022
Physics Department, California State University San Marcos

Associate Professor, 2015-present
Physics Department, California State University San Marcos

Visiting Scholar, 2015
Quantum Design, Inc.

Assistant Professor, 2009-2015
Physics Department, California State University San Marcos

Visiting Assistant Professor, 2008-2009 
Physics Department, California State University San Marcos

Adjunct Instructor, 2007
Physical Sciences Department, Houston Community College -- Central Campus

Research Assistant, 2002-2008
Texas Center for Superconductivity, University of Houston

Selected Professional Memberships

American Physical Society (APS)
American Association of Physics Teachers (AAPT)
Sigma Pi Sigma Physics Honor Society
CSUSM Asian Pacific Islander Desi American Faculty & Staff Association (APIDA-FSA)
Phi Kappa Phi National Honor Society
Golden Key International Honour Society
Alpha Lambda Delta-Phi Eta Sigma Honor Societies
University of Houston Alumni Association