Biography

Janez Stepisnik was born on 6. April 1940 in Ljubljana. He received his bachelor’s degree in physics in 1964, his master's degree in 1968, and his Doctor of Physics Science was defended in 1971. In 1963-1966 he was a technical associate of the development laboratory for high-frequency telecommunications at the ISKRA company, and in 1966-1971 he was a young researcher at the J. Stefan Institute. In 1971 he became an assistant professor and in 1975 was elected to the teaching title at the Department of Physics, University of Ljubljana. In 1973-74, he was an associate researcher at the University of Washington in Seattle, USA. His research area was magnetic resonance methods with an emphasis on the study of magnetic resonance imaging in a weak magnetic field, the development and introduction of a new NMR method for the study of molecular dynamics in liquids, polymers, heterogeneous systems, and in research on the properties of substances with ultrasound. In 1994-95, he was a visiting professor at the Massey University of New Zealand where, with P T. Callaghan, had realized idea of the development of a new method for measuring the spectrum of molecular velocity auto- correlations in liquids. In  sabbatical year from 2002 to 2004 he presented his research in a series of invited lectures at the Wageningen University, the Netherlands, at the RWTH, Aachen, Germany,  at the Massachusetts Institute of Technology in Cambridge, USA, at the Schlumberger-Doll Research, Institute,  USA,  at the University of California, Berkeley, USA, at  New Mexico Resonance Institute, Albuquerque, USA, at the Institute for Polymers, Dresden, Germany,  at the University of Montana in the Bozeman, USA, and at the faculty of Medicine of the University of Harvard in Boston, USA.

 In 1984-86 he was president of the Society of mathematicians, physicists and astronomers of Slovenia. In 1990-92 he was the head of the Department of Physics, University of Ljubljana. He organized 14. European experimental NMR conference in Bled in 1998 and was president of the International Committee of European experimental NMR conferences in 2000-2005. Since 2003, he has been a permanent lecturer of the international AMPERE NMR Summer School in Poland. At the Department of Physics, his teaching includes Physical practicum, Physics I, Modern physics, Physics of energy resources at the undergraduate level and Nonlinear optics at the postgraduate level. As a visiting professor at the Massey University of New Zealand, he conducted teaching of Experimental physics and Modern physics and the Basics of polymer physics. Student reviews of his lectures were very positive.

He retired as a university teacher in 2009 and was  elected to the title of Professor Emeritus of the University of Ljubljana. He continues to do research and lecture at international meetings.

Research achievements

In 1986, he unveiled a method that utilized a low- geomagnetic field for magnetic resonance imaging, that might significantly reducing the cost of MR imaging equipment. By 2005, he  also refined the NMR-modulated spin echo gradient technique, expanding its frequency range beyond 10 kHz. This advancement facilitated the study of translational diffusion in excited granular systems, restricted diffusion in nano-pore environments, and molecular dynamics within liquids and polymers. The findings from a study on the molecular dynamics of glycerin and water mixtures reveal a potential mechanism that enables biomolecules to spontaneously fold from a disordered state to a biologically active configuration. Collaborating with A. Mohorič, they have recently (2023-25) developed a novel NMR technique that allows for the measurement of fluctuations in molecular conformations during chemical reactions.

In 1977, he received the national scientific Fund Award for achievements in NMR measurements of molecular translational dynamics, and in 1985, the same Fund Award for a patent in the field of ultrasound.

His bibliography includes more than 300  publications in international scientific journals, books and proceedings of international conferences with more than 3000 citations, where the most frequently mentioned are:

· Analysis of NMR self-diffusion measurements by a density matrix calculation" in Physica B+C,

· The cement hydration measured by ultrasonic" in Ceramic Bulletin, 1981

· Spatially-Distributed Pulsed Gradient Spin Echo NMR using Single-Wire Proximity " in Physical Review Letters, 1995,

· Generalized Analysis of Motion Using Magnetic Field Gradients" in the book series Advances in Magnetic and Optical Resonance, vol. 19, Academic Press 1996,

· Autocorrelation spectra of an air-fluidized granular system measured by NMR" in Europhysics Letters, 2006,

· NMR down to Earth" in Nature, 2006,

· NMR in the Earth's magnetic field " in Progress in NMR Spectroscopy, Pergamon Press 2009,

· Self-diffusion in nanopores studied by the NMR pulse gradient spin echo" in EuroPhysics Letters, 2012,

· Velocity autocorrelation spectra in molten polymer measured by NMR modulated gradient spin-echo", in EuroPhysics Letters, 2014,

· Usage of internal magnetic fields to study the early hydration process of cement paste by MGSE method", in Journal of Magnetic Resonance, 2016,

· Molecular velocity auto-correlations in glycerol/water mixtures studied by NMR MGSE method, in Physica A: Statistical Mechanics and its Applications, 2020.

· Polymer Dynamics in Glycerol–Water Mixtures, in Molecules, 2023.

· NMR of chemical exchange:revisited, in Journal of Magnetic Resonance, 2025.