Colloquium on "Complex System Science and Nonlinear Dynamics (CSSN-colloquium)"

Onsager relations, nonequilibrium phase transitions and absolute negative mobility

Abstract: The understanding of the underlying dynamical mechanisms which determines the macroscopic laws of heat conduction is a long standing task of non-equilibrium statistical mechanics. A better understanding of such mechanism may also lead to potentially interesting applications based on the possibility to control the heat flow, and to new theoretical results. In particular we discuss the possibility of absolute negative mobility (ANM) which is a highly counterintuitive phenomenon, where the sign of the induced current is opposite to the applied forces.

We also provide analytical and numerical evidence that Onsager reciprocal relations remain valid for systems with broken time-reversal symmetry as is typically the case when a generic magnetic field is present. Hence, the fundamental constraints that Onsager relations impose on heat to work conversion remain valid also with broken time-reversal symmetry. In particular, the possibility of an engine operating at the Carnot effciency with finite power is ruled out on purely thermodynamic grounds.


[1] G. Benenti, G. Casati, K. Saito, and R. S. Whitney, Phys. Rep. 694 (2017) 1.

[2] J. Wang and G. Casati, Phys. Rev. Lett. 118 (2017) 040601.

[3] Rongxiang Luo, G. Benenti, G. Casati, and Jiao Wang, Phys. Rev. X 2, 022009(R) (2020)

[4] Jiao Wang, G. Casati, and G. Benenti Phys. Rev. Lett. 124 (2020) 110607.

Абстракт: Понимание основных динамических механизмов, определяющих макроскопические законы теплопроводности - важнейшая задача неравновесной статистической механики. Лучшее понимание такого механизма также может привести к потенциально интересным применениям, основанным на возможности управления транспортом тепла и к новым фундаментальным результатам. В данном докладе, мы обсуждаем возможность абсолютно отрицательной мобильности, которая является крайне противоречивым явлением, когда знак наведенного тока противоположен приложенным силам.

Мы также предоставляем аналитические и численные доказательства того, что взаимные отношения Онзагера остаются в силе для систем с нарушенной симметрией относительно обращения времени, как это обычно бывает при наличии общего магнитного поля.

Giulio Casati (Center for Complex Systems, University of Insubria and Lake Como School of Advanced studies Como, Italy)

Bio: Giulio Casati is Emeritus Professor of Theoretical Physics at Insubria University. Casati is known for his work on chaos, both classical and quantum, being considered one of the pioneers of the latter. Casati is in fact principally known for the discovery of quantum dynamical localization phenomenon, that highlighted the relevance of chaos in quantum mechanics. His landmark paper, with Boris Chirikov, Joseph Ford and Felix Izrailev, is among the most quoted in the field. With Boris Chirikov, Italo Guarneri and Dima Shepelyansky Casati also discovered that quantum localization deeply affects the excitation of hydrogen atom in strong monochromatic fields. Further major contributions considered the connections between quantization of non integrable systems and the statistical theory of spectra. With the advent of quantum computing Casati and his coworkers studied the efficient quantum computing of complex dynamics. On the classical side, Casati's interests regarded mostly energy conduction in non-linear lattices: from the earliest numerical proof of the validity of Fourier law in one-dimensional many body systems, obtained in collaboration with Bill Wisscher, Franco Vivaldi, and Joseph Ford, to the description of a thermal rectifier and of a thermal transistor. The same techniques lead to the theoretical demonstration of a one-way mirror for light.

Casati has received the Italian Prize for Physics "F. Somaini" (1991), the Enrico Fermi Prize (2008)(the most important Italian prize for Physics), the Premio internazionale per la fisica della Accademia Nazionale dei Lincei (2010), the Sigillo Longobardo (2010). He is a Member of the Academia Europaea and is the author/coauthor of over 300 publications.