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News & Events
News
Archive
Corinna Kollath is APS fellow
Corinna Kollath became fellow of the American Physical Society in 2020 "for studies of low dimensional correlated systems, in particular out of equilibrium, using a combination of analytic and novel numerical approaches".
Congratulations!
Dispersions of many-body Bethe strings observed
Theoretical physicist Hans Bethe predicted in 1931 that complex bound states of magnons – Bethe strings – could exist in one-dimensional quantum magnets. After the first experimental observation in 2018, Dr. Zhe Wang (Institute of Physics II, University of Cologne) together with colleagues from Berlin, Cologne, Didcot, Dresden, Grenoble, Mumbai, Shanghai and Vancouver now report further experimental evidence for the existence of the many-body string states in a one-dimensional quantum magnet in the journal Nature Physics.
Walter Schottky prize for Zhe Wang
Dr. Zhe Wang receives the Walter Schottky prize "For his pioneering work in the field of quantum magnetism, in particular for the experimental detection of so-called Bethe strings using THz spectroscopy at very high magnetic fields."
Events
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RESEARCH PROFILE
COLLABORATIVE RESEARCH CENTER 1238
Control and Dynamics of Quantum Materials
Spin orbit coupling, correlations, and topology
Advances in materials science are one of the strongest drivers of technological innovations and thereby shape our daily life, though often in an unseen way. Powerful examples from recent years include the advent of novel memory technologies building on magnetoresistance read/write heads, ferroelectric, and phase-change memories. The discovery of fascinating materials like graphene has led to a worldwide surge of research initiatives for innovative applications of these and other novel two dimensional materials. Spin-orbit coupled materials such as the recently discovered topological insulators from a new class of solids that have a strong potential for novel functionalities.
Material-based technological innovations are more often than not initiated on the basic-science level through discoveries of new concepts, phenomena, and principles governing the physical properties of quantum materials. Research on quantum materials is a rapidly developing and internationally highly competitive interdisciplinary field. At the forefront of this field, new materials are being investigated in which relativistic spin-orbit effects and non-trivial topologies are at center stage. At the same time, materials with strong electronic correlations exhibit a wealth of non-trivial quantum ordering phenomena including superconductivity, magnetism, and other exotic orders. Precisely at the intersection of these research fields, our collaborative research center aims at exploring, understanding, developing, and utilizing quantum materials to gain deliberate control of the physical properties of these materials and to understand their dynamics, explore driven states of matter, and enable new functionalities.
Our diverse team of principle investigators includes scientists from experimental and theoretical physics as well as crystallography, building and expanding on the excellent research infrastructure in Cologne embedded in the Excellence Initiative key profile area 'quantum matter and materials'. The Cologne team is augmented by excellent scientists with indispensable expertise from the University of Bonn and the Forschungszentrum Jülich. Guiding philosophies of our program are the ‘materials - physical properties - theory' cycle, which is one of the cornerstones of the success of condensed-matter physics at the University of Cologne, and a multifaceted approach arising from addressing scientific topics from a variety of different perspectives as defined in the focus areas of the program.
The CRC will consolidate and expand Cologne together with the associated groups from Bonn and Jülich as a leading international center within quantum condensed-matter physics. Our vision is to discover, understand, and control novel collective phenomena in quantum materials arising from the interplay of spin-orbit coupling, correlations, and topology.
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TEAM OF PRINCIPAL INVESTIGATORS
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Yoichi Ando
A04 / /
topological materials,
superconductivity,
materials synthesis,
transport measurements
Nicolae Atodiresei
first principles simulations,
molecular nanostructures,
hybrid interfaces, molecular
electronics and spintronics
Petra Becker-Bohatý
crystal chemistry,
structural crystallography,
crystal growth, crystal physics,
materials science
Stefan Blügel
theory of electronic properties of real solids, spintronics,
low-dimensional systems,
spin-orbit related phenomena
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Ralf Bulla
theory of condensed matter,
quantum phase transitions,
quantum impurity physics,
renormalization group methods
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Alexander Grüneis
2D materials: synthesis and
functionalization photoelectron spectroscopy
Raman spectroscopy
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Joachim Hemberger
broadband dielectric and optical spectroscopy, frustrated magnetism,
ferroelectrics, multiferroics,
spin-ice, (quantum-)critical dynamics
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Corinna Kollath
correlated many body systems, non-equilibrium phenomena in quantum
systems, numerical many-body physics
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FORMER PRINCIPAL INVESTIGATORS
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Maria Hermanns
theory of condensed matter,
strongly correlated systems,
quantum spin liquids, entanglement, fractional quantum Hall effect
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Fan Yang
exp.condensed matter physics,
topological materials,
transport measurements,
nano-device fabrication
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PROJECTS
Project Area A
Materials – preparation and characterization
A01 (Grüneis / Michely)
Spin-orbit coupling and many-body effects in novel 2D materials
A02 (Becker-Bohatý / Braden / Lorenz)
Crystal growth and design of materials
A04 (Ando / Yang)
Project Area B
Physical properties
B01 (Lorenz / Ando)
B02 (Grüninger / Hemberger)
From mHz to PHz: Broadband dielectric and optical spectroscopy
of quantum matter
B03 (van Loosdrecht / Grüninger)
Inelastic photon scattering in spin-orbit-coupled matter
B04 (Braden)
Dynamics and correlations studied by neutron scattering
B05 (van Loosdrecht)
B06 (Michely / Ando)
Project Area C
C01 (Atodiresei / Blügel)
Structure inversion-asymmetric matter and spin-orbit
phenomena from ab-initio
C02 (Rosch / Trebst)
Spin-orbit driven topological and correlated states and
Dirac matter
C03 (Trebst / Diehl / Bulla)
Thermodynamics of fractionalization in spin-orbit entangled
matter
C04 (Diehl / Rosch)
Dynamics of topological and correlated states of matter
C05 (Kollath)
Theory
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Participating institutes
CONTACT
Prof. Dr. Paul van Loosdrecht
II. Physikalisches Institut
Universität zu Köln
Zülpicher Str. 77
50937 Köln
Tel: +49 221 470 2707
pvl@ph2.uni-koeln.de
Speaker
II. Physikalisches Institut
Universität zu Köln
Zülpicher Str. 77
50937 Köln
Tel.: +49 221470 -2106 or -6998
berthet@ph2.uni-koeln.de
Administrative coordinator
II. Physikalisches Institut
Universität zu Köln
Zülpicher Str. 77
50937 Köln
Tel: +49 221 470 3659
koethe@ph2.uni-koeln.de
Scientific coordinator
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