MELVILLE, N.Y., May 11, 2023 – Chaos congratulates Yuzuru Kato, Thomas Lilienkamp, and Tiemo Pedergnana for winning the journal’s 2022 Edward N. Lorenz Early Career Awards.
Kato was recognized for introducing a definition of a phase function for quantum rhythmic systems, which will aid analysis of quantum synchronization. Lilienkamp was commended for developing a low-energy and safer approach to defibrillation, a treatment for cardiac arrhythmias that often leads to severe side effects. Pedergnana was selected for work to better understand if and how an exact potential, which greatly simplifies analysis of the Langevin equation, can be found for a given system.
The winners were chosen by a committee of Chaos editors. They will split a $2,000 honorarium and are invited to contribute a perspective article to the journal.
Chaos authors can self-identify as candidates for this award during submission of their manuscripts. In order to be eligible, the first author must either have received their doctorate in the past five years, received their master's degree within the past eight years, or be a current student (times from degree exclude career breaks such as parental leave).
Kato was selected for his paper “A definition of the asymptotic phase for quantum nonlinear oscillators from the Koopman operator viewpoint” published in Chaos on June 24, 2022.
Kato earned his doctorate from Tokyo Institute of Technology in 2020 and was a postdoctoral researcher there until 2022. Currently an associate professor at Future University Hakodate, he focuses on the interdisciplinary combination of nonlinear dynamics and quantum physics.
“I try to provide mathematical frameworks for analyzing quantum nonlinear dynamics and unveil the qualitative difference between classical and quantum nonlinear dynamics from a mathematical viewpoint,” said Kato.
Spontaneous oscillations and synchronization are observed in a wide variety of classical rhythmic systems, including heartbeats and flashing fireflies. Recent progress in nanotechnology has facilitated similar analysis of rhythm and synchronization in quantum systems, such as optomechanical oscillators and atomic ensembles.
“In this work, we introduced a definition of a phase function for quantum rhythmic systems,” said Kato. “This is useful for the analysis of quantum synchronization.”
The proposed phase function is a natural extension of the classical phase function.
“This original definition of an asymptotic phase function provides appropriate phase values for characterizing quantum nonlinear oscillators,” said Jürgen Kurths, editor-in-chief of Chaos.
Because the asymptotic phase plays a fundamental role in the analysis of classical limit-cycle oscillations and synchronization, Kurths thinks the proposed phase function will have a strong impact on technology.
“I feel for the first time that I have made a contribution to the scientific community,” said Kato. “I would be grateful if more researchers became interested in quantum synchronization and other nonlinear phenomena in open quantum systems through this work.”
Lilienkamp was recognized for his paper “Taming cardiac arrhythmias: Terminating spiral wave chaos by adaptive deceleration pacing” published in Chaos on Dec. 13, 2022.
Now a professor at the Nuremberg Institute of Technology, Lilienkamp completed the winning research during a postdoctoral fellowship at the Max-Planck Institute for Dynamics and Self-Organisation in Göttingen, Germany, where he also obtained his doctorate.
His work explores the fundamental mechanisms underlying cardiac arrhythmias using numerical simulations, with a goal to create efficient control strategies and improve medical treatments for patients. Part of this includes developing low-energy defibrillation strategies to reduce the severe side effects associated with their high-energy counterparts.
“In our study, we suggest that the temporal distances between consecutive shocks should be coordinated/adapted to the underlying dynamics of the cardiac muscle during ventricular fibrillation,” said Lilienkamp.
The suggested pacing protocol starts with fast pulses and ends with slower ones, all of which cover the frequencies and time scales of the heart’s underlying dynamics. Numerical simulations showed the method can synchronize and control the chaotic dynamics in an efficient way.
“Current treatments of ventricular fibrillation induce substantial electrical currents in the myocardium and are associated with significant side effects, including additional tissue damage and post-traumatic stress,” said Kurths.
Kurths believes this new pulse protocol, called deceleration pacing, represents major progress toward new, gentle low-energy defibrillation methods.
“This award is a great honor for me and encourages me to continue working on such interesting topics with such wonderful collaborators,” said Lilienkamp. “Based on our study, we want to investigate how we can further improve the current low-energy approaches.”
Pedergnana was commended for his paper “Exact potentials in multivariate Langevin equations” published in Chaos on Dec. 30, 2022.
As a doctoral student at ETH Zürich, Pedergnana conducts theoretical, experimental, and numerical research in acoustics for combustion and metamaterial applications. He is interested in developing new methods for the analysis of dynamical systems, with a focus on applying them to real-world experiments.
“I work on acoustics for power generation and metamaterial applications. Fundamentally, we are trying to understand the phenomenon of whistling in various configurations and how it can be controlled and manipulated,” said Pedergnana. “Concurrently, we are studying dynamical systems theory to enhance our methods of analysis.”
A Langevin equation can describe how many dynamical systems evolve. If the equation has an exact potential, its analysis is greatly simplified. In the winning paper, Pedergnana and his colleagues studied differential-geometric transformation properties of the Langevin equation to better understand if and how an exact potential can be found for a given system.
“Langevin equations govern a broad class of dynamical systems describing biological, chemical, physical, and financial processes,” said Kurths. “The differential-geometric approach taken by the authors to seek hidden exact potentials could be expanded to a broader class of dynamical systems.”
According to Kurths, this should lead to fruitful research and exciting new results in the field of nonlinear and stochastic dynamics.
“I am happy and honored to receive this award. It shows me that people care about our work, which is, in the end, all that matters,” said Pedergnana. “Chaos is an outstanding journal and I have been a reader for many years, which makes this all the better.”
The article “A definition of the asymptotic phase for quantum nonlinear oscillators from the Koopman operator viewpoint” is authored by Yuzuru Kato and Hiroya Nakao. It can be accessed at https://doi.org/10.1063/5.0088559.
The article “Taming cardiac arrhythmias: Terminating spiral wave chaos by adaptive deceleration pacing” is authored by Thomas Lilienkamp, Ulrich Parlitz, and Stefan Luther. It can be accessed at https://doi.org/10.1063/5.0126682.
The article “Exact potentials in multivariate Langevin equations” is authored by Tiemo Pedergnana and Nicolas Noiray. It can be accessed at https://doi.org/10.1063/5.0124031.
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Chaos is devoted to increasing the understanding of nonlinear phenomena in all areas of science and engineering and describing their manifestations in a manner comprehensible to researchers from a broad spectrum of disciplines. See https://aip.scitation.org/journal/cha.