Basic Information

Complex Systems Modeling Laboratory
Senior Associate Professor
Web site


Courses - Undergraduate
Electronic circuits, Electromagnetism
Courses - Graduate
Advanced Devices for Computer and Communication Systems, Modeling of Advanced Semiconductor Devices


Physics and computer modeling of nanoelectronic devices, Biophysical modeling
Educational Background, Biography

2003 Assistant/Associate Professor, University of Aizu
1998(03-09) Visiting Researcher, Chalmers University of Technology
1993 Research Associate, University of Aizu
2001 D.Eng., Tokyo Institute of Technology
1992 M.S., Moscow Institute of Physics and Technology

Current Research Theme
Theory and computer modeling: Graphene nanoelectronic devices, Detectors and generators of Terahertz radiationModeling of cardiac electrical conduction system and ECG
Key Topic
Computer Modeling, Monte Carlo method, Nonlinear Systems, Oscillators
Affiliated Academic Society
IEEE Electron Devices Society (EDS, Senior Member), IEEE Engineering in Medicine and Biology Society (EMBS), American Physical Society


Skiing, Trekking, Swimming
School days' Dream
Current Dream
Live as if you were to die tomorrow. Learn as if you were to live forever.
Favorite Books
Messages for Students
Always desire to learn something useful
Publications other than one's areas of specialization

Main research

Computer modeling of cardiac electrical system

Our team at the University of Aizu is studying the heart's electrical activity using a simple harmonic motion model of the heart. We are studying arrhythmia and chaos mechanisms in the heart. The non-linear dynamics model of our heart is capable of reproducing heart signaling system behavior for regular and irregular states. You can join us in possibly making many interesting discoveries as we study the heart's electrical activity using computer simulations.

Our model enables simulations of the workings of the heart's conducting system as oscillators linked mutually which include vibrating pacemaker cells and excitatory muscles.

We are researching the following topics:

  • Different types of pacemaker cells and cardiac muscles;

  • Cardiac disease;

  • Artificial heart pacemakers;

  • The impact of external stimuli on heartbeats

We are developing a system that incorporates a mounted FPGA (a heart-on-a-chip) that is quick for assessments, comparatively simple, and that can perform calculations efficiently, in closed-loop systems and software and hardware tests for pacemakers and defibrillators (ICDs) using this model.

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Computer modeling of nanoelectronic devices based on graphene heterostructures

The increase in computer speed over the past few decades is notable, but it is coming to an end. One factor is that silicon itself has reached physical limits.
Recently, however, a new material, graphene, has been discovered that allows electrons to flow faster than silicon. Graphene consists of carbon atoms arranged in a single atom sheet. This is also a component of graphite forming a general pencil.
Graphene transistors can run electrons 100 to 1,000 times faster than today's silicon transistors.
The computer models developed in this research and the original simulation software are used to investigate the behavior of different graphene-based nanoelectronic devices such as FETs, detectors, and lasers.

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Dissertation and Published Works

Selected publications:
  • M. Ryzhii, T. Otsuji, V. Ryzhii, V. Mitin, M.S. Shur, G. Fedorov, and V. Leiman. "Dynamic conductivity and two-dimensional plasmons in lateral CNT networks", Int. Journal of High Speed Electronics and Systems, 26 (1-2), art. no. 1740004, 2017.
  • M.A. Quiroz-Juárez, R. Vázquez-Medina, E. Ryzhii, M. Ryzhii, and J.L. Aragón. "Quasiperiodicity route to chaos in cardiac conduction model", Communications in Nonlinear Science and Numerical Simulation, 42, pp. 370-378, 2017.
  • M. Ryzhii and E. Ryzhii. "Simulink heart model for simulation of the effect of external signals", CIBCB 2016 - Annual IEEE Int.Conference on Computational Intelligence in Bioinformatics and Computational Biology, art. no. 7758102, 2016.
  • E. Ryzhii and M. Ryzhii. "A heterogeneous coupled oscillator model for simulation of ECG signals," Computer Methods and Programs in Biomedicine, 117(1), pp. 40-49, 2014.
  • M. Ryzhii, V.Ryzhii, T. Otsuji, P.P. Maltsev, V.G. Leiman, N. Ryabova, and V. Mitin. "Double injection, resonant-tunneling recombination, and current-voltage characteristics in double-graphene-layer structures," Journal of Applied Physics, 115(2), 024506 (1-8), 2014.
  • T. Otsuji, S. Boubanga Tombet, A. Satou, M. Ryzhii, and V. Ryzhii. "Terahertz-wave generation using graphene: Toward new types of terahertz lasers," IEEE J. of Selected Topics in Quantum Electronics, 19(1), 8400209(9), 2013.
  • M. Ryzhii, T. Otsuji, V. Mitin, and V. Ryzhii. "Characteristics of p-i-n terahertz and infrared photodiodes based on multiple graphene layer structures," Japanese Journal of Applied Physics, 50, pp. 070117 (6), 2011.
  • M. Ryzhii, V. Ryzhii, T. Otsuji, V.Mitin, and M.S. Shur. "Electrically induced n-i-p junctions in multiple graphene layer structures," Physical Review B, 82, 075419 1-6, 2010.
  • M. Ryzhii and V. Ryzhii. "Physics and modeling of tera- and nano-devices," World Scientific Publishing Co Pte Ltd., Singapore, 2008.
  • M. Ryzhii, V. Ryzhii, and M.S. Shur. "Effect of near-ballistic photoelectron transport on resonant plasma-assisted photomixing in high-electron mobility transistors," Semiconductor Science and Technology, 19(4), pp. S74-S76, 2004.
  • M. Ryzhii and V. Ryzhii. "Monte Carlo modeling of transient recharging processes in quantum-well infrared photodetectors," IEEE Transactions on Electron Devices, 47(10), pp. 1935-1942, 2000.
  • M. Ryzhii, M. Willander, I. Khmyrova, and V. Ryzhii. "Terahertz response of metal-semiconductor-metal photodetectors," Journal of Applied Physics, 84(11), pp. 6419-6425, 1998.