ConQuMat - TRR360

Introduction to the electronic lab book ELabFTW
2024-10-30 09:00 - 10:30 (Europe/Berlin)
An introduction to the electronic lab book eLabFTW is scheduled for next Wednesday, October 31st at 9:00 a.m. in the seminar room of EPII (room 344, north) at the University of Augsburg.This will be a hybrid seminar, conducted in parallel online.The Zoom link and login details are provided by email to all TRR 360 staff members.

TRR 360 Seminar: Hidden multipolar order and singlet magnetism in f-electrons systems Sergii Khmelevskyi
2024-10-22 16:00 - 17:00 | University of Augsburg, Room S-288 + Zoom
Hidden multipolar order and singlet magnetism in f-electrons systems
Dr. Sergii Khmelevskyi
TU Wien
The nature of order in low-temperature phases of some materials is not directly seen by experiment. Such “hidden orders” (HOs) may inspire decades of research to identify the mechanism underlying those exotic states of matter. In insulators, HO phases originate in degenerate many-electron states on localized f-shells that may harbor high-rank multipole moments. We show how the ground-state order and magnetic excitations of a prototypical HO system NpO2, can be fully described by a low-energy Hamiltonian derived by a many-body ab initio force theorem method. A primary non collinear order of time odd rank 5 (triakontadipolar) moments has been predicted. We show also that exotic non-chiral magnetic order in PrO2 is a results of a strong high order multipolar interactions within whole |JM> ground state multiplet. The multipolar interactions also leads to the peculiar magnetization process in PrO2 resulting in the exotic meta-magnetic transition in the applied magnetic field and fully dominate the ordinary dipolar Heisenberg exchange.
As has been shown by Kotliar and Haule in 2007 the canonical and perhaps most investigated metallic “hidden” order materials URu2Si2 can also develop a “hidden” multipolar order (hexadecapolar) due to localized 5f2 configuration at low temperature. Whereas at higher temperatures a hybridization of the localized 5f-levels leads to the Kondo behavior (“Kondo arrest scenario”) and at very low temperature a hidden order phase coexists with superconductivity. We reveal on basis of correlated ab-intio calculations a close analogy between normal state behavior of URu2Si2 and newly discovered heavy fermion UTe2 superconductor.

Venue

Focus Lecture
2024-10-18 10:30 - 12:00 | University of Augsburg Room S-403, Universitätsstrasse 2, Augsburg, 86159
We are pleased to invite you to the first focus lecture organized within the framework of the MGK project of TRR360.

Dr. Joachim Deisenhofer has kindly agreed to “break the ice” with the following topic:

“THz Time-Domain Spectroscopy in Magnetic Insulators”

In this lecture, Dr. Deisenhofer will introduce the basic concepts of THz time-domain spectroscopy, covering both

theoretical and experimental aspects. The talk will be structured into two key parts:

Basic Principles: A discussion on the foundational concepts of THz time-domain spectroscopy, including how to extract optical material parameters, such as the complex refractive index, from raw data.

Experimental Insights: The second part will highlight experimental results from insulating magnets, particularly in materials such as the magnetoelectric compound Fe₂Mo₃O₈ and the ferrimagnetic spinelFeCr₂S₄.

The lecture is scheduled for October 18th at 10:30 AM in Room 403S at the Institute of Physics, University of Augsburg.

PhD students are strongly encouraged to attend in person and share this email with interested colleagues. (There will be a bonus for those attending in person.)

For those who cannot join in person, the lecture will also be transmitted via Zoom. The Zoom link was send around via e-mail.

Retreat Meeting 2024
2024-10-10 12:00 - 2024-10-11 16:00 | Schloss Hirschberg, Hirschberg 70, Beilngries, 92339, Germany
From 10th to 11th of October all members of the TRR360 meet at castle Hirschberg in Beilngries to share latest results and discuss organizational topics of the TRR.

The program can be downloaded here:

Programm_Retreat Meeting 2024Download

Workshop: Strong and confident in the application process
2024-10-09 12:00 - 20:00 | Schloss Hirschberg, Hirschberg 70, Beilngries, 92339, Germany
Only for our young female researchers!
In this workshop we will look at our strengths, learn about how to built up more self-confidence and how we successfully present ourself during a job application.

MGK Workshop
2024-08-28 08:00 - 2024-08-30 17:00 | Haus der bayerischen Landwirtschaft, Rieder Str. 70, Herrsching am Ammersee, 82211, Germany
The first MGK Workshop will take place in Herrsching am Ammersee!
Many scientific presentations from young researchers, a Gender equality and Diversity workshop, swimming in the Ammersee and many nice hours together are awaiting you. Here, you can check out the detailed MGK Workshop program.
See you in Herrsching!

TRR 360 Seminar: Strain Tuning of Frustrated Magnets and Mott Insulators: Stress Reduces Frustration Andrej Pustogov
2024-07-23 16:00 - 17:00 | University of Augsburg, Room S-288 + Zoom
Strain Tuning of Frustrated Magnets and Mott Insulators: Stress Reduces Frustration
Andrej Pustogov TU Wien
Tuning materials properties on demand is at the heart of condensed matter science. Charge transport and magnetism are strongly linked to the overlap of electronic wave functions and can be, thus, manipulated by varying the electronic bandwidth through chemical substitution or physical pressure. Yet, a controlled variation of the symmetry, anisotropy and frustration of transfer integrals and exchange interactions remained inaccessible so far.
Here, we explore Mott insulators subject to strong antiferromagnetic interactions, where geometrical frustration suppresses magnetic order entirely [1,2] or down to very low temperatures TN << J [4,7]. Utilizing the recent advancements in strain tuning of unconventional superconductors [8,9], we apply uniaxial stress to fine-tune the Mott transition with unprecedented precision in a triangular-lattice compound [2]. Through the slope of the metal-insulator boundary in the temperature-pressure phase diagram we pinpoint the nonmagnetic ground state of the most intensely studied quantum-spin-liquid candidate [1-3]. By applying in situ uniaxial pressure to a clean, well-studied kagome-lattice compound without disorder [4-6], we obtain direct control of antiferromagnetic order within one single crystal [7]. As the applied stress reduces the frustration strength, TN is enhanced by 10% [7]. Our pioneering endeavors [2,7] demonstrate uniaxial strain as a powerful tool to tune interacting spins on frustrated lattices – towards stabilizing novel, exotic, possibly even quantum entangled spin states.
[1] B. Miksch, A. Pustogow, M. Javaheri Rahim, A. A. Bardin, K. Kanoda, J. A. Schlueter, R. Hübner, M. Scheffler, M. Dressel, Science 372, 276-279 (2021)[2] A. Pustogow, Y. Kawasugi, H. Sakurakoji, N. Tajima, Nat. Commun. 14, 1960 (2023)[3] Y. Kawasugi, S. Yamazaki, A. Pustogow, N. Tajima, J. Phys. Soc. Jpn. 92, 065001 (2023)[4] P. Puphal, M. Bolte, D. Sheptyakov, A. Pustogow, K. Kliemt, M. Dressel, M. Baenitz, C. Krellner, J., Mater. Chem. C 5, 2629 (2017)[5] T. Biesner et al., Adv. Quantum Technol. 2022, 2200023 (2022)[6] D. Chatterjee et al., Phys. Rev. B 107, 125156 (2023)[7] Jierong Wang, Y.-S. Su, M. Spitaler, K.M. Zoch, C. Krellner, P. Puphal, S.E. Brown, and A. Pustogow, Phys. Rev. Lett. 131, 256501 (2023)[8] C.W. Hicks et al., Science 344, 283 LP (2014)[9] A. Chronister et al., npj Quantum Mater. 7, 113 (2022)

Venue

TRR 360 Seminar: Discerning and mitigating complex quantum correlations in many-body dynamics Jan Budich
2024-07-17 14:00 - 15:00 | Technical University Munich + Zoom
Discerning and mitigating complex quantum correlations in many-body dynamics
Jan BudichTU Dresden
The proliferation of complex quantum correlations in many-body dynamics poses a formidable challenge both to quantum information science at a fundamental level and to classical variational approaches such as tensor network methods at a practical computational level. In this talk, after a brief introduction to the broader field, we discuss two of our recent contributions towards discerning various sources of quantum correlations and mitigating dynamical growth of entanglement. First, noting that entanglement depends on how a system is partitioned into subsystems (entanglement cut), we explore the potential of dynamically adjusting the entanglement cut as a strategy for reducing entanglement growth. Second, regarding the dynamics of mixed states such as locally perturbed thermal states, we demonstrate how tools from differential geometry such as parallel transport can be harnessed to tame the temporal growth of quantum correlations in a purified state corresponding to the physical mixed state.

Venue

MGK industry visit
2024-07-15 13:00 - 17:00 | Attocube Systems AG, Eglfinger Weg 2, Haar, 85540, Germany
Interested MGK young researchers can visit two leading companies in quantum technologies in Munich.
The first one is Attocube Systems AG (Eglfinger Weg 2, 85540 Haar, https://www.attocube.com/en), which is known for its precision nanopositioning systems. We will meet there at 1 pm.
At 4 pm the second tour starts at the Kiutra GmbH (Flößergasse 2, 81369 Munich, https://kiutra.com/). This company is renowned for its advancements in cryogen-free refrigeration .

TRR 360 Sonderseminar: Optimization and Application for Cryogenic Magnetic Refrigeration Using Yb-based Intermetallic Compounds Yasuyuki Shimura
2024-06-28 10:00 - 11:00 | University of Augsburg, Room 242-R
Optimization and Application for Cryogenic Magnetic Refrigeration Using Yb-based Intermetallic Compounds
Prof. Dr. Yasuyuki Shimura
Hiroshima University, Japan

Venue

TRR 360 Sonderseminar: Ultrafast spin-orbitronics with terahertz electromagnetic pulses Tobias Kampfrath
2024-06-27 14:00 - 15:00 | University of Augsburg, Room S-288 + Zoom
Ultrafast spin-orbitronics with terahertz electromagnetic pulses
Tobias Kampfrath
Freie Universität Berlin and Fritz Haber Institute of the Max Planck Society, Berlin

To take advantage of the electron spin in future electronics, spin angular momentum needs to be transported and detected. Electric fields and temperature gradients have been shown to efficiently drive spin transport at megahertz and gigahertz frequencies. However, to probe the initial elementary steps that lead to the formation of spin currents, we need to launch and measure transport on much faster, i.e., femtosecond time scales.
To achieve this goal, we apply optical femtosecond laser pulses to induce a spin voltage in a metallic ferromagnetic layer F [1]. The resulting spin current into an adjacent layer is measured by conversion into a charge current in a layer N and detection of the concomitantly emitted terahertz electromagnetic pulse [2]. Interesting applications such as terahertz spin-conductance spectroscopy [3] and the generation of ultrashort terahertz electromagnetic pulses emerge [4]. In all cases, the emitted terahertz signal arises from regions close to the F/N interface, thereby making spintronic terahertz emission very interface-sensitive [5]
This methodology can be transferred from the spin to the so far highly unexplored orbital angular momentum of electrons. We obtain new insights into orbitronic phenomena on their natural time scales, for example, time-domain signatures of giant propagation lengths of orbital currents in tungsten [6].
Finally, one can implement a reciprocal experimental scheme and use intense terahertz electromagnetic pulses to drive electric currents and control magnetic order on ultrafast time scales through, for example, Néel spin-orbit torques [7].

References[1] Rouzegar et al., Phys. Rev. B 106, 144427 (2022)[2] Kampfrath et al., Nature Nanotech. 8, 256 (2013)[3] Rouzegar et al., arXiv:2305.09074 (2023)[4] Seifert et al., Nature Photon. 10, 483 (2016); Rouzegar et al., Phys. Rev. Appl. 19, 034018 (2023)[5] Gueckstock et al., Advanced Materials 33, 2006281 (2021)[6] Seifert et al., Nature Nanotech. 18, 1132-1138 (2023)[7] Behovits et al., Nature Communications 14, 6038 (2023)

Figure: Schematic of optically driven spin-orbitronic emission of ultrabroadband terahertz electromagnetic pulses from a generic F|N thin-film stack. 𝑴 is the magnetization of layer F.

Venue

TRR 360 Seminar: Fractionalized magnetization plateaus with hidden discrete degeneracy in metallic Kagome spin ice HoAgGe Kan Zhao
2024-06-25 16:00 - 17:00 | University of Augsburg, Room S-288 + Zoom

TRR 360 Seminar: Twisted Bilayer Graphene: a platform for heavy fermion physics Roser Valenti
2024-06-12 14:00 - 15:00 | Technical University Munich + Zoom
Twisted Bilayer Graphene: a platform for heavy fermion physics
Roser ValentiGoethe-Universität Frankfurt am Main
After a brief introduction to TBG, we will discuss its correlated and topological properties and put forward a heavy fermion description. We will show through a combination of Hartree-Fock (HF) and Dynamical Mean Field Theory (DMFT) that such a heavy fermion picture is able to describe in a unified way many of the experimentally observed features in these materials.

Venue

TRR 360 Sonderseminar: Structure and magnetism of LMO/SMO superlattices Vasily Moshnyaga
2024-06-11 16:00 - 17:00 | University of Augsburg, Room S-288 + Zoom
Structure and magnetism of LMO/SMO superlattices
Prof. Dr. Vasily MoshnyagaI. Physikalisches InstitutGeorg-August-Universität Göttingen
Heterostructures of strongly correlated oxides, like superlattices (SLs) of (LaMnO3)m/(SrMnO3)n ((LMO)m/(SMO)n), provide a rich platform for searching emergent phases at the interfaces as well as to design artificial electronically/chemically inhomogeneous materials to study the manifestations of electron-spin-lattice correlations in reduced dimensions. We studied the structure and magnetism of the LMO/SMO SLs prepared on SrTiO3(100) substrates by metalorganic aerosol deposition (MAD) technique. The role of interfacial charge transfer in the high-TC emergent ferromagnetism and the interrelations between the octahedral tilt/rotation angle, controlled by LMO/SMO ratio, and magnetic/thermal properties have been elucidated. Further on, we have grown LMO/SMO SLs with gradual La/Sr compositional modulations on the scale 5-10 u.c. and studied their role in the development of high- and low-temperature magnetic phases. We propose a route to grow strongly correlated heterostructures with modulated electronic properties at the nanoscale.

Venue

TRR 360 Sonderseminar: Microwave spectrum analyzer based on a rapidly tuned spin-torque nano-oscillator Andrei Slavin
2024-06-11 14:00 - 15:00 | Technical University Munich + Zoom
Microwave spectrum analyzer based on a rapidly tuned spin-torque nano-oscillator
Andrei Slavin
Department of Physics, Oakland University, Rochester, MI 48309, USA
A spintronic method of ultra-fast broadband microwave spectrum analysis is proposed. It uses a rapidly tuned spin torque nano-oscillator (STNO) and does not require injection locking. This method treats an STNO generating a microwave signal as an element with an oscillating resistance. When an external signal is applied to this “resistor” for analysis, it is mixed with the signal generated by the STNO. The resulting mixed voltage contains the “sum” and “difference” frequencies, and the latter produces a DC component when the external frequency matches the frequency generated by the STNO. The mixed voltage is processed using a low pass filter to exclude the “sum” frequency components and a matched filter to exclude the dependence of the resultant DC voltage on the phase difference between the two signals. It is found analytically and by numerical simulation that the proposed spectrum analyzer has a frequency resolution at a theoretical limit in a real-time scanning bandwidth of 10 GHz and a frequency scanning rate about 20 MHz /ns, while remaining sensitive to signal power as low as the Johnson-Nyquist thermal noise floor.

Andrei Slavin received PhD degree in Physics in 1977 from the St.Petersburg Technical University, St. Petersburg, Russia. Dr. Slavin developed a state-of-the-art theory of spin-torque oscillators, which has numerous applications in the theory of current-driven magnetization dynamics in magnetic nanostructures. His current research support includes multiple grants from the U.S. Army, DARPA, SRC and the National Science Foundation. This research involves international collaborations with leading scientists in many countries, including Germany, Ukraine, France, Italy, and the United States. Dr. Slavin is a frequently invited speaker at magnetism conferences around the world.
Andrei Slavin is Fellow of the American Physical Society, Fellow of the IEEE, and Distinguished Professor and Chair of the Physics Department at the Oakland University, Rochester, Michigan, USA.

Venue

TRR 360 Seminar:Exploring quantum impurities and measurement backaction via tensor-networksOded Zilberberg
2024-05-22 14:00 - 15:00 | Technical University Munich + Zoom
Exploring quantum impurities and measurement backaction via tensor-networks
Oded Zilberberg
Universität Konstanz

Tensor networks allow us to compress and efficiently represent one-dimensional many-body states. This relies on truncating small correlations and entanglement along the system’s length. At the same time, the representation provides easy access to these correlations. My talk will be divided into three parts: (i) I will introduce a mesoscopic coupled quantum-dots system, map it onto a Wilson chain, and show how to study Kondo physics via the tensor network correlations as order parameters, (ii) I will introduce how the tensor network description of a mixed state provides an easy-to-read entanglement measure for open systems, and (iii) show how the entanglement measure allows us to better understand measurement-induced transitions (MITs).

Venue

Steering Committee Meeting
2024-05-14 12:00 - 13:00

TRR 360 Seminar: Altermagnetism: spin symmetry prediction and photoemission observation Libor Šmejkal
2024-05-07 16:00 - 17:00 | University of Augsburg, Room S-288 + Zoom
Altermagnetism: spin symmetry prediction and photoemission observation

Libor ŠmejkalUniversity of Mainz

Venue

TRR 360 Seminar: Quantum criticality on compressed lattices Markus Garst
2024-04-24 14:00 - 15:00 | Technical University Munich + Zoom
Quantum criticality on compressed lattices
Prof. Dr. Markus Garst
Karlsruher Institut für Technologie

At a quantum phase transition, the ground state of a system changes as a function of a non-thermal control parameter. In a solid, the associated quantum critical degrees of freedom generically couple to the crystal lattice. This coupling is potentially able to change the universality class of the quantum critical point. We discuss various scenarios where this is realised. The coupling is necessarily non-perturbative when the order parameter couples bilinearly to strain as it is the case for quantum critical endpoints or nematic quantum criticality [1]. If the strain couples only to the square of the order parameter, it is non-perturbative at weak coupling if the effective dimension d+z, with the spatial dimension d and the dynamical exponent z, is smaller than 2/ν, where ν is the correlation length exponent. This criterion is, for example, marginally fulfilled at a Lifshitz transition of a two-dimensional metal like Sr2RuO4 [2]. We discuss in detail the quantum phase transition in the O(N) universality class with dynamical exponent z=1, and we show that non-perturbative effects might also arise if this criterion is not fulfilled but the coupling exceeds a critical threshold [3].
[1] I. Paul and M. Garst, Phys. Rev. Lett. 118, 227601 (2017).[2] H. M. L. Noad et al. Science 382, 447 (2023)[3] S. Sarkar, L. Franke, N. Grivas and M. Garst, Phys. Rev. B 108 235126 (2023).

Venue

TRR 360 Sonderseminar: Magnetic field versus temperature phase diagram of an effective spin-1/2 zigzag chain in a magnetic semiconductor YbCuS2 Takahiro Onimaru
2024-03-11 11:30 - 12:30 | University of Augsburg, Room S-288 + Zoom
Magnetic field versus temperature phase diagram of an effective spin-1/2 zigzag chain in a magnetic semiconductor YbCuS2
Prof. Dr. Takahiro Onimaru
Graduate School of Advanced Science and Engineering, Hiroshima University, Japan

Venue

2. Steering Committee Meeting
2024-02-19 13:00 - 16:00 | Zoom Conference

TRR 360 Seminar: Controlled quantum materials Daniele Fausti
2024-01-30 16:00 - 17:00 | University of Augsburg, Room S-288 + Zoom
Controlled quantum materials
D. Fausti 1,2,3
1 Department of Physics, University of Trieste, Trieste
2 Elettra Sincrotrone Trieste S.c.p.a., Trieste
3 Department of Physics, University of Erlangen Nuremberg
The rich phase diagrams of many transition metal oxides (TMOs) is the result of the intricate interplay between electrons, phonons, and magnons. This makes TMOs very susceptible to external parameters such as pressure, doping, magnetic field, and temperature which in turn can be used to finely tune their properties. The same susceptibility makes TMOs the ideal playground to design experiments where the interaction between tailored electromagnetic fields and matter can trigger the formation of new, sometimes exotic, physical properties. This aspect has been explored in time domain studies [1] and has led to the demonstration that ultrashort mid-IR light pulses can “force” the formation of quantum coherent states in matter, disclosing a new regime of physics where thermodynamic limits may be bridged and quantum effects can, in principle, appear at ambient temperatures.
In this presentation I will review our recent results in archetypal strongly correlated cuprate superconductors and demonstrate the feasibility of a light-based control of quantum phases in real materials [2,3,4]. I will then introduce our new approaches to time domain spectroscopy going beyond mean photon number observables [5-10] and show that the statistical features of light can provide information on superconducting fluctuations beyond standard linear and non-linear optical spectroscopies [11]. Finally, I will elaborate on our current research effort to use cavity electrodynamics to control fluctuations in matter and thereby the onset of quantum coherent states in complex materials [12].
References:
[1] Advances in Physics 65, 58-238, 2016
[2] Science 331, 189-191 (2011)
[3] Phys. Rev. Lett. 122, 067002 (2019)
[4] Nature Physics 17, 368–373 (2021)
[5] Phys. Rev. Lett. 119, 187403 (2017)
[6] New J. Phys. 16 ,043004 (2014)
[7] Nat. Commun. 6, 10249 (2015)
[8] PNAS March 19, 116 (12) 5383-5386 (2019)
[9] J. of Physics B 53, 145502 (2019)
[10] Optics Letters 45, 3498 (2020)
[11] Light: Science & Applications 11, # 44 (2022)
[12] Nature 622, 487–492 (2023)

Venue

1. Steering Committee Meeting
2024-01-25 11:00 - 12:00 | Zoom Conference

TRR 360 Seminar: Broadband optical studies of kagome metals Ece Uykur
2024-01-16 16:00 - 17:00 | University of Augsburg, Room S-288 + Zoom
Broadband optical studies of kagome metals: Electronic correlations, localized
carriers and phonons
Ece Uykur
Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum
Dresden-Rossendorf, 01328, Dresden, Germany

Kagome metals attract a lot of attention as materials that combine two extreme features in their
electronic structure: Massless Dirac fermions with linear band dispersion and flat bands hosting massive
localized electrons. Topological nature of the former and strongly correlated nature of the latter lead to
multitude of exotic phenomena, including quantum anomalous Hall effect and novel states, such as axion insulators. The electron dynamics of these systems is the key for understanding the proposed exotic phenomena.
To this end, we employed broadband infrared and ultrafast pump-probe spectroscopy studies on
series of kagome metals. In this talk, I will summarize the optical fingerprints of itinerant and localized
carriers, signatures of electronic correlations, and the interplay between unconventional carriers and
phonons in these systems.

Venue

TRR 360 Seminar: Magneto-optical detection of topological contributions to the anomalous Hall effect in kagome magnets Sándor Bordács
2023-12-05 16:00 - 17:00 | University of Augsburg, Room S-288 + Zoom
Venue

Young Researchers Forum 2023
2023-11-28 10:00 - 2023-11-29 16:00 | University of Augsburg, Universitätsstr. 2, Augsburg, 86159
This 2-day event will be used as an ice breaker for the members of the MGK. The young researcher get the chance to get to know each other. First young researchers present topics related to their work. The Ö-project gives a presentation about Educational Escape Games and ideas of the young researchers for the Quantum Escape Game of the Ö-projects shall be discussed.

TRR 360 Sonderseminar: The unusual electron transport in metallic Kagome nets Philip J. W. Moll
2023-11-08 17:00 - 18:00 | University of Augsburg, Room S-288 + Zoom
The unusual electron transport in metallic Kagome nets
Prof. Dr. Philip J. W. Moll
Max Planck Institute for the Structure and Dynamics of Matter

Materials that can host different states of electronic order form a recurring theme in physics and
materials science, and they are of particular interest if they are coupled strongly. A famous
example are ferroelectrics, in which electric polarization and magnetism not only coexist but are
strongly linked. This both unveils a rich physics of correlated states, and also opens unexpected
application avenues as the coupling promises to manipulate one state by a stimulus that primarily
acts on another – say switching magnetism using electric fields.
Recently, materials based on the structural motif of the Kagome web have attracted significant
attention for their tendency to host such strongly coupled phases. In particular, the centro-
symmetric layered Kagome metal (K,Cs)V3Sb5 have entered the focus of experimental and
theoretical research. They host a charge-density-wave type transition at elevated temperatures
~100K, followed by a superconducting transition at 3K (exact values depend on composition).
Yet there is another type of electronic order which thus far eludes exact microscopic
identification. A series of experimental probes detects the onset of anomalous behavior around
T’~30-40K, including thermal Hall, µSR, NMR, magnetic torque, Kerr rotation. The anomalous
low-temperature state carries the characteristics of a chiral, nematic and time-reversal-symmetry
breaking fluid (all of which are under most active debate currently).
Yet what crystallizes out of the current state of experimental data is a highly entangled system
which is extraordinarily responsive to external perturbations. This materials main strength is
equally its weakness, the unusual degree of coupling between states can hinder its systematic
investigation. However, it is already clear that it provides a platform to explore strongly coupled
correlated phases, and as a result it displays a thus-far unknown electromagnetic response, a
diode in which the forward direction can be switched by the application of a magnetic field. I
will review the current state of the field, and discuss ongoing projects in my department.

[1] C. Guo et al., Nature 611, 461-466 (2022)
[2] X. Huang et al., PRB 106, 064510 (2022)

Venue

Retreat Meeting 2023
2023-10-09 - 2023-10-10 | Kloster Irsee, Klosterring 4, Irsee, 87660, Germany
The first project retreat meeting of TRR360 – ConQuMat takes place at Kloster Irrsee. There, all project members get together to introduce their research plans and subprojects as well as get to know each other.
