Bust of Max Planck

Highlights

Publication Highlights

How tissues respond to mechanical stress

Underlying mechanism of cell viscoelasticity revealed

Epithelial tissues like our skin are made of cells that are tightly connected through E-Cadherin – a protein that binds adjacent cells together. These tissues respond differently to forces from the environment. When they are subjected to forces for a short duration they behave like an elastic band, whereas, when subjected to the same force for a longer duration they show viscous behavior like honey. This property of tissues, called viscoelasticity, plays a key role to understand tissue shape changes during embryonic development. Although viscoelasticity is a well-known property, the molecular mechanisms underlying such viscoelastic behavior of developing tissues were largely unknown, so far.
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Publication Highlights

Measuring the single-particle density matrix in an optical lattice

L. A. Peña Ardila et al., Phys. Rev. Lett. 121, 260401 (2018)

Ultracold atoms in optical lattices provide clean, tunable, and well-isolated realizations of paradigmatic quantum lattice models. With the recent advent of quantum-gas microscopes, they now also offer the possibility to measure the occupations of individual lattice sites. What, however, has not yet been achieved is to measure those elements of the single-particle density matrix, which are off-diagonal in the occupation basis. Here, we propose a scheme to access these basic quantities both for fermions as well as hard-core bosons and investigate its accuracy and feasibility.
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Awards and Honors

Physik-Preis Dresden

Am 15. Januar 2019, 17 Uhr, wird der „Physik-Preis Dresden“ des Max-Planck-Instituts für Physik komplexer Systeme (MPI-PKS) und der TU Dresden zum dritten Mal verliehen. Der Preisträger ist der Physiker Prof. Dr. Klaus Richter. Die Preisverleihung findet am Max-Planck-Institut für Physik komplexer Systeme statt.
Prof. Dr. Klaus Richter, theoretischer Festkörperphysiker an der Universität Regensburg, erhält den diesjährigen „Physik-Preis Dresden“ für seine herausragenden theoretischen Beiträge zur semiklassischen Physik. Seine jüngeren innovativen und anspruchsvollen Ansätze zur semiklassischen Quantisierung von Vielteilchen Systemen mit Hilfe periodischer Bahnen, entwickelt zusammen mit Juan-Diego Urbina, setzen wichtige semiklassische Ergebnisse zur spektralen Statistik chaotischer Systeme fort, erzielt zusammen mit Martin Sieber zu Beginn der 2000er Jahren. Sie knüpfen auch an die wegweisende semiklassische Deutung mesoskopischer Phänomene mit Hilfe periodischer Bahnen, die Klaus Richter in der Gruppe von Nobelpreisträger Klaus v. Klitzing in Stuttgart, Mitte der 90iger Jahre, entwickelte.
Klaus Richter betreibt theoretische Physik auf hohem intellektuellen Niveau mit dem Anspruch wirklich neue Einsichten zu gewinnen. Mit seiner wissenschaftlichen Breite bietet er wertvolle Anregung sowohl für die Physiker der TU Dresden als auch des MPI-PKS.
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. 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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Awards and Honors

Anne E. B. Nielsen receives Sapere Aude: DFF-Starting Grant

The Independent Research Fund Denmark awards Anne E. B. Nielsen a Sapere Aude starting grant of 789436 euro to carry out the project "Anyons in new settings". The purpose of the Sapere Aude initiative is to reward the most accomplished young researchers and scientists with original ideas and provide the opportunity to carry out research at the highest international level.
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Publication Highlights

Collisionless Transport Close to a Fermionic Quantum Critical Point in Dirac Materials

B. Roy et al., Phys. Rev. Lett. 121, 137601 (2018)

Dirac fermions are realized as low-energy excitations in a wide class of condensed matter systems, such as graphene and surface states of topological insulators. These so-called Dirac materials are rather stable against weak Hubbard-like local interactions. However, at strong interactions they may undergo quantum phase transitions into broken symmetry phases, such as spin- and charge-density-waves. The question then arises what may be the possible experimental imprints of such a quantum phase transition in terms of observable. Researcher from MPIPKS in collaboration with Nordita recently showed that the frequency-dependent electrical conductivity at both zero and finite temperature gets suppressed in the close vicinity to such critical point in comparison to its counterpart in a noninteracting system. Such peculiar, but universal behavior stems from strong interactions among wildly fluctuating gapless fermionic and bosonic order-parameter excitations inside the quantum critical regime, occupied by a relativistic non-Fermi liquid.
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Institute's News

New Clusters of Excellence for the TU Dresden - The MPIPKS is part of two new Dresden clusters

The German Research Foundation (Deutsche Forschungsgemeinschaft) announced the new Clusters of Excellence in the framework of the Excellence Strategy of the German Federal and State Governments. The TU Dresden received three new Clusters of Excellence: "Physics of Life", "Center for Tactile Internet", and "Complexity and Topology in Quantum Materials" jointly with the University of Würzburg. The Max Planck Institute for the Physics of Complex Systems is involved in two of the new Dresden Clusters: "Physics of Life" and “Complexity and Topology in Quantum Materials".
- "Physics of Life"
- “Complexity and Topology in Quantum Materials"
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Institute's News

Open letter to the residents of Dresden

Publication Highlights

Global Phase Diagram of a Dirty Weyl Liquid and Emergent Superuniversality

B. Roy et al., Phys. Rev. X 8, 031076 (2018)

Weyl semimetals are exotic materials in which electrons behave more like photons - massless particles moving at a relativistic speed. However, it is unclear how well Weyl semimetals hold on to their bizarre properties in real disordered materials that are littered with impurities. Researchers from MPIPKS in collaboration with Nordita show that for small amounts of disorder such gapless topological semiconductors are stable, but at intermediate disorder these systems can undergo a quantum phase transition into a metallic phase, where electrons cease to behave as relativistic particles. Intriguingly, they discovered that the nature of this continuous transition is insensitive to the many (if not all) details of impurities, a phenomenon commonly referred to as superuniversality, which leaves its signature on the behavior of various observables, such as specific heat and electrical conductivity. These features combined with several other known transitions constitute the global phase diagram of disordered Weyl systems.
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Publication Highlights

Resonance eigenfunction hypothesis for chaotic systems

K. Clauß et al., Phys. Rev. Lett. 121, 074101 (2018)

Classical systems with particles escaping through an opening are quantum mechanically described by resonance eigenfunctions. They are for example important for scattering experiments, like emission from optical microcavities, and show fractal patterns which strongly depend on their decay rate. The resonance eigenfunction hypothesis put forward in the paper provides a detailed understanding of this fractal structure. It is based on classical properties of the chaotic dynamics with a new time scale given by the temporal distance to the so-called chaotic saddle. Numerical support is presented for a chaotic map with escape.
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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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