Bust of Max Planck

Highlights

Publication Highlights

Floquet Engineering of Optical Solenoids and Quantized Charge Pumping along Tailored Paths in Two-Dimensional Chern Insulators

Botao Wang et al., Phys. Rev. Lett. 120, 243602 (2018)

The adiabatic creation of single quasipartices or quasiholes via the insertion of one magnetic flux quantum through an infinitely thin solenoid is a famous gedanken experiment of quantum-Hall physics. In the present paper, physicists from Dresden show how this scenario can be realized in a real experiment with ultracold atoms in optical lattices. For this purpose, they propose a scheme for engineering "optical solenoids", tunable artificial magnetic fields piercing a single plaquette of an optical lattice. Moreover, they investigate how this technique can be used for quantized charge pumping along tailored paths in two dimensional topological Chern insulators.
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Awards and Honors

Biophysicist Frank Jülicher elected for EMBO membership

Frank Jülicher, director of the Max Planck Institute for the Physics of Complex Systems (MPI-PKS) and the CSBD, is one of 62 outstanding life scientists, that have been elected to the European Molecular Biology Organization (EMBO). With his election, the biophysicist is joining a group of over 1800 EMBO researchers in Europe and around the world.
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Institute's News

New Research Group: Computational Quantum Many-Body Physics

Welcome David Luitz! David heads the new research group "Computational Quantum Many-Body Physics" which will study strongly interacting quantum matter and in particular phenomena that arise due to the presence of many particles. Using computational many-body techniques such as exact diagonalization and tensor network methods, both equilibrium and nonequilibrium properties of strongly interacting quantum systems will be investigated, in particular in the context of periodic driving, dissipation and strong disorder.
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Publication Highlights

Driven-Dissipative Supersolid in a Ring Cavity

F. Mivehvar et al., Phys. Rev. Lett. 120, 123601 (2018)

Supersolids, a mysterious phase of matter consisting of a crystal which can flow without friction, have been elusive to experimental confirmation till last year, where the first realisations using ultracold atomic systems have been achieved. These atomic implementations however take place in driven-dissipative systems, a situation which lies outside the?thermal equilibrium scenario so far considered in theory.
In this work, we study for the first time the effect of the openness of the system on the main features of a supersolid, and find that its hallmarks can be robust against drive and dissipation whenever the latter preserve spatial translation invariance.
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Institute's News

New Research Group: Mesoscopic Physics of Life

We are glad to announce the arrival of Dr. Christoph A. Weber, who heads the research group ‘Mesoscopic Physics of Life' since March 1, 2018. The group is interested in intra-cellular organisation and aims in particular to understand the role of phase transitions inside cells, including the impact of phase separation and protein aggregation during development and in the context of disease. Further interests are to unravel physical principles underlying the early formation of proto-cells at the origin of life.
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Awards and Honors

Markus Heyl receives the 2018 Bernhard Heß prize

The distinction is awarded to outstanding young scientists by the University of Regensburg. Markus Heyl receives the prize for his contributions to the field of nonequilibrium quantum many-body systems and, in particular, for the development of the theory of dynamical quantum phase transitions. The prize is donated with 2.000 Euro, and the awardees are invited to give a guest lecture at the University of Regensburg.
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Publication Highlights

Universality of clone dynamics during tissue development

S. Rulands et al., Nature Physics (2018)

The development of an organism relies on the tightly orchestrated behavior of many cells. How do these cells self-organize in order to build complex structures like the heart or the brain? To achieve this the fate of these cells must be precisely regulated and understanding the mechanisms of cell fate regulation is key for treating diseases that occur upon dysregulation, such as cancer or diabetes. The fate behaviour of stem and progenitor cells is reflected in the time evolution of their progeny, termed clones, which serve as a key experimental observable. But what can we actually learn from such clones about the processes that regulate their fate during development? Drawing on the results of genetic tracing studies, we show that, despite the complexity of organ development, clonal dynamics may converge to a critical state characterized by universal scaling behaviour of clone sizes. We show how this identification of universal scaling dependences may allow lineage-specific information to be distilled from experiments. Our study shows the emergence of core concepts of statistical physics in an unexpected context, identifying cellular systems as a laboratory to study non-equilibrium statistical physics.
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Publication Highlights

Dynamical quantum phase transitions: a review

M. Heyl, Rep. Prog. Phys. (2018)

Quantum theory provides an extensive framework for the description of the equilibrium properties of quantum matter. Yet experiments in quantum simulators have now opened up a route towards generating quantum states beyond this equilibrium paradigm. While these states promise to show properties not constrained by equilibrium principles such as the equal a priori probability of the microcanonical ensemble, identifying general properties of nonequilibrium quantum dynamics remains a major challenge especially in view of the lack of conventional concepts such as free energies. The theory of dynamical quantum phase transitions attempts to identify such general principles by lifting the concept of phase transitions to coherent quantum real-time evolution. This review provides a pedagogical introduction to this field. Starting from the general setting of nonequilibrium dynamics in closed quantum many-body systems, we give the definition of dynamical quantum phase transitions as phase transitions in time with physical quantities becoming nonanalytic at critical times. We summarize the achieved theoretical advances as well as the first experimental observations, and furthermore provide an outlook onto major open questions as well as future directions of research.
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Publication Highlights

Topological Classification of Crystalline Insulators through Band Structure Combinatorics

Jorrit Kruthoff et al., Phys. Rev. X 7, 041069

Topological insulators are exotic materials that are electrical insulators in their interior but can conduct electricity on their surface, and their discovery has fundamentally changed our understanding of how phases of matter may be organized. Most phases of matter are categorized by the symmetries that they break. Crystals break translational symmetry, magnets break rotational symmetry, and so on. Topological insulators, however, show that some phases can be distinct even though their symmetries are equal. Researchers have come up with a classification scheme--called the tenfold way--which allows for the categorization of topological phases depending on some general properties, such as whether or not they have time-reversal or particle-hole symmetry. We complement this categorization by providing a method for listing all possible topologically distinct phases of matter that do not have external symmetries but do have the types of internal (or lattice) symmetries that appear in the atomic arrangements of real solid materials. We explicitly list all possible phases in two-dimensional materials and provide an intuitive and easily applicable method for identifying the phases possible within a given lattice type in any dimension. Our method matches the known results based on the mathematically involved predictions of K-theory, which is known to be a rigorous way of identifying all possible topological phases. It thus provides insight into this mathematical arena based on a physical understanding of topological band structures. We also show how our method can be used to study the transitions between topological phases and predict whether they will result in topologically protected Weyl semimetals. This new classification can now be used to guide the search for new types of topological materials and related edge modes or exotic intermediate phases.
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Awards and Honors

"Physik-Preis Dresden“ zum zweiten Mal verliehen

Am Dienstagabend, dem 5. November 2017, wurde der „Physik-Preis Dresden“ der TU Dresden und des Max-Planck-Instituts für Physik komplexer Systeme (MPI-PKS) zum zweiten Mal verliehen. Preisträger ist der französische Physiker Prof. Dr. Jacques Prost, emeritierter CNRS Forschungsdirektor am Institut Curie in Paris. Prof. Jacques Prost erhielt den Preis für seine herausragenden wissenschaftlichen Verdienste in der Anwendung der Physik des Nichtgleichgewichts auf vielfältige Fragestellungen in der Biologie. Er ist der internationale Pionier in der mesoskaligen Physik biologischer Systeme. Mit seinen originellen und kreativen Ideen hat Jacques Prost neue Konzepte zur Erforschung biologischer Systeme etabliert und die Rolle physikalischer Prinzipen in der Biologie hervorgehoben. Als ein regelmäßiger Gast in Dresden hat er die Entwicklung der Dresdner biophysikalischen Gemeinschaft wesentlich vorangetrieben und zu zahlreichen Forschungsaktivitäten an der Schnittstelle zwischen Physik und Biologie angeregt. Der Gastgeber des Abends, Prof. Roland Ketzmerick, Sprecher der Fakultät Physik der TU Dresden, war überaus erfreut, dass mit Jacques Prost eine so bedeutende internationale Forscherpersönlichkeit geehrt wurde. „Ich wünsche der Dresdner Biophysik auch weiterhin hervorragende Kooperationen mit ihm“, so Ketzmerick. Zurzeit arbeitet Prost intensiv an dem Projekt "Physik aktiver Gele und des Zellskeletts" mit Prof. Stephan Grill vom BIOTEC (TU Dresden) und Prof. Frank Jülicher vom MPI-PKS zusammen. Die Auszeichnung mit dem „Physik-Preis Dresden“ sei für ihn eine große Ehre, und er bedankte sich mit einigen deutschen Worten bei Preisstifter Peter Fulde, der Preis-Jury sowie seinen Eltern, die ihn die Bedeutung der Freundschaft innerhalb Europas von Anfang an gelehrt haben. „Ich habe in Dresden echte Freunde gefunden“, betonte Prost. Der „Physik-Preis Dresden“ wurde 2015 von dem Dresdner Physiker Prof. Peter Fulde, dem Gründungsdirektor des MPI-PKS gestiftet. Die Preisträger werden von einer gemeinsamen Jury der TU Dresden und des MPI-PKS bestimmt, deren diesjähriger Vorsitzender Prof. Dr. Matthias Vojta von der Fakultät Physik ist. Neben dem zentralen Kriterium der wissenschaftlichen Exzellenz ist für die Entscheidung vor allem wichtig, dass die Arbeiten der Preisträger für die Zusammenarbeit zwischen beiden Dresden-concept-Partnern MPI-PKS und TU Dresden von besonderer Bedeutung sind und deren Verbindung langfristig weiter gestärkt wurde.
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