Projects / Programmes
Many-body transport engineering
| Code |
Science |
Field |
Subfield |
| 1.02.02 |
Natural sciences and mathematics |
Physics |
Theoretical physics |
| Code |
Science |
Field |
| P190 |
Natural sciences and mathematics |
Mathematical and general theoretical physics, classical mechanics, quantum mechanics, relativity, gravitation, statistical physics, thermodynamics |
| Code |
Science |
Field |
| 1.03 |
Natural Sciences |
Physical sciences |
quantum transport, many-body systems, nonequilibrium physics, spin chains, quantum physics, statistical physics, one-dimensional systems, open systems
Researchers (7)
Organisations (1)
Abstract
Statistical physics and its sister thermodynamics are very successful theories for which Einstein have said that it is a universal theory that, within its applicability, will never be overthrown by a better theory. Validity of statistical physics namely does not rest on specific microscopic laws that are eventually replaced by a more complete description, but rather on universal properties that hold for local observables in any system with a large number of degrees of freedom. And exactly this universality is a beauty that Einstein very much appreciated.
Statistical physics can be divided into an equilibrium one and a nonequilibrium one. Equilibrium physics is well known, developed in the 2nd half of the 18th century by the likes of Boltzmann and Gibbs. It finds its applicability in pure hard core science like physics, other natural sciences such as biology and chemistry, as well as in engineering, for instance in the dynamics of (heat) engines.
Nonequilibrium physics is on the other hand much less explored, particularly with respect to possible universality, simply because it by definition encompasses a much greater variety of phenomena -- everything that is not equilibrium. Therefore, if we seek some simple universal description one has to first limit oneself to a suitable subset of nonequilibrium physics. What is the simplest such situation? Opinions will of course differ, but one can argue that one of the simplest situations is when a state is independent of time. Such a state is called a nonequilibrium steady state (NESS). A simple example would be a wire connected to a voltage source. After some initial transient a steady state forms in which a constant current flows through the wire. Studying transport -- the simplest nonequilibrium phenomenon -- is the goal of the proposed project.
We want to understand transport in many-body systems where particle interactions (correlations), potential disorder, as well as quantum coherence play a role. An interplay between these effects can guarantee a rich variety of transport behaviors. We would like to stress that nonequilibrium phenomena are at the forefront of present day theoretical physics as well as cutting-edge experimental efforts moving towards simulation of condensed-matter systems or in general quantum simulators. Expected results will therefore be important for several areas, namely, fundamentals of nonequilibrium statistical physics, transport in strongly correlated systems of condensed matter, and last but not least to learn about design principles of interesting new future materials. The last point -- design principles -- would be of high interest both from an engineering point of view as well as for the developing field of quantum information where designer materials with special properties are also highly sought-for. It needs not be stressed that transport in itself is a basic required functionality in many every-day devices (electricity conduction, transport based devices like diodes, transistors,...).
In the project we shall study transport in simple low-dimensional many-body systems, with an emphasis on 1D quantum models. Some recent results of our group [1] gives us confidence to tackle an even more ambitious question, changing the research paradigm. Namely, so far one typically studied transport in a given model, amassing a zoology of specific transport behaviors for concrete models. From that it is not easy to see general rules. We instead propose a paradigm shift to the question what are the design properties that lead to a model with a given transport type. Given a transport type, how can we design a model that has such transport?
Literature:
[1] M. Znidaric and M. Ljubotina, Interaction instability of localization in quasiperiodicystems, Proc. Natl. Acad. Sci. U.S.A. 115, 4595 (2018).
Significance for science
Expected project results will have an impact on several layers of science and specific field of nonequilibrium physics. Transport is one of fundamental nonequilibrium properties, and is as such of interest in theoretical physics, however, due to its widespread use in everyday life it has also strong applied component. Our project will study simple model systems with the aim of getting fundamental understanding of what determines the transport type (e.g., superconductivity vs. diffusion).
Specifically, we shall explore and focus on non-diffusive transport (among other, anomalous) as it can lead to interesting phenomena and uses. We will understand when can one have a superdiffusive transport. Present results hint that one needs integrabilty as well as an additional symmetry (like SU(2) or SU(4)), details are however not understood. Second, we will also focus on transport that is slower than diffusive. This can arise due to non-fully localizing disorder. Here we touch upon a very interesting field of many-body localization and new phases of matter that do not fully thermalize. Of especial interest are intermediate phases that for instance show very slow relaxation, or total absence thereof for some states. Such phases would be of immense use in quantum information theory -- a rapidly developing field studied in academia and industry -- as they could for instance be used in quantum memory.
We also plan to explore the ``engineering'' approach to transport where we plan to design a required (anomalous) transport by e.g. engineered disorder. Recently we also found that disorder with spatial correlations can lead to very interesting behavior, and in particular to high controllability of transport -- a small perturbation can lead to a big change in transport.
All the above mentioned findings of anomalously fast or slow transport, as well as of controllability by small changes, could lead to interesting new devices. An example would be thermal or electric rectification with very high gain. That aspect, being part of our WP3, has potentially strong applied component. Understanding what can lead to higher rectification factor, or high ZT figure of merit for thermoelectricity, could advance materials science bringing us a step closer to making thermoelectric cooling competitive to ordinary ``gas expansion'' refrigerating techniques (for that we would need about a 3-fold increase in ZT).
Topics studied are of high interest to several fields that are at the forefront of current physics research. We have demonstrated our excellence and high impact in the past and expect that the results of the proposed research will do the same (members of the project team have in the last 5 years published 18 papers in Physical Review Letters as well as in other high-impact journals like Nature Communications, PNAS, Physical Review X, 4 of those papers are highlighted as ``Highly Cited in the Field'' by WoS citation database).
Significance for the country
Expected project results will have an impact on several layers of science and specific field of nonequilibrium physics. Transport is one of fundamental nonequilibrium properties, and is as such of interest in theoretical physics, however, due to its widespread use in everyday life it has also strong applied component. Our project will study simple model systems with the aim of getting fundamental understanding of what determines the transport type (e.g., superconductivity vs. diffusion).
Specifically, we shall explore and focus on non-diffusive transport (among other, anomalous) as it can lead to interesting phenomena and uses. We will understand when can one have a superdiffusive transport. Present results hint that one needs integrabilty as well as an additional symmetry (like SU(2) or SU(4)), details are however not understood. Second, we will also focus on transport that is slower than diffusive. This can arise due to non-fully localizing disorder. Here we touch upon a very interesting field of many-body localization and new phases of matter that do not fully thermalize. Of especial interest are intermediate phases that for instance show very slow relaxation, or total absence thereof for some states. Such phases would be of immense use in quantum information theory -- a rapidly developing field studied in academia and industry -- as they could for instance be used in quantum memory.
We also plan to explore the ``engineering'' approach to transport where we plan to design a required (anomalous) transport by e.g. engineered disorder. Recently we also found that disorder with spatial correlations can lead to very interesting behavior, and in particular to high controllability of transport -- a small perturbation can lead to a big change in transport.
All the above mentioned findings of anomalously fast or slow transport, as well as of controllability by small changes, could lead to interesting new devices. An example would be thermal or electric rectification with very high gain. That aspect, being part of our WP3, has potentially strong applied component. Understanding what can lead to higher rectification factor, or high ZT figure of merit for thermoelectricity, could advance materials science bringing us a step closer to making thermoelectric cooling competitive to ordinary ``gas expansion'' refrigerating techniques (for that we would need about a 3-fold increase in ZT).
Topics studied are of high interest to several fields that are at the forefront of current physics research. We have demonstrated our excellence and high impact in the past and expect that the results of the proposed research will do the same (members of the project team have in the last 5 years published 18 papers in Physical Review Letters as well as in other high-impact journals like Nature Communications, PNAS, Physical Review X, 4 of those papers are highlighted as ``Highly Cited in the Field'' by WoS citation database).
Most important scientific results
Interim report
Most important socioeconomically and culturally relevant results
