Publications/Talks

2024
Pb₁₀₋ₓ Cuₓ(PO₄)₆O: a Mott or charge transfer insulator in need of further doping for (super)conductivity,
L. Si, M. Wallerberger, A. Smolyanyuk, S. Di Cataldo, J. M. Tomczak, and K. Held,
J. Phys.: Condens. Matter 36, 065601 (2024), DOI: 10.1088/1361-648X/ad0673

2023
Absence of electron-phonon-mediated superconductivity in hydrogen-intercalated nickelates,
S. Di Cataldo, P. Worm, L. Si, and K. Held,
Phys. Rev. B 108, 174512 (2023), DOI: 10.1103/PhysRevB.108.174512

Topotactic hydrogen forms chains in ABO2 nickelate superconductors,
L. Si, P. Worm, D. Chen, and K. Held,
Phys. Rev. B 107, 165116 (2023), DOI: 10.1103/PhysRevB.107.165116

No superconductivity in Pb₉Cu₁(PO₄)₆O found in orbital and spin fluctuation exchange calculations,
N. Witt, L. Si, J. M. Tomczak, K. Held, and T. O. Wehling,
SciPost Phys. 15, 197 (2023), DOI: 10.21468/SciPostPhys.15.5.197

Electronic structure of the putative room-temperature superconductor Pb₉Cu(PO₄)₆O,
L. Si and K. Held,
Phys. Rev. B 108, L121110 (2023), DOI: 10.1103/PhysRevB.108.L121110

Nonlinear responses and three-particle correlators in correlated electron systems exemplified by the Anderson impurity model,
P. Kappl, F. Krien, C. Watzenböck, and K. Held,
Phys. Rev. B 107, 205108 (2023), DOI: 10.1103/PhysRevB.107.205108

2022
Density matrix of electrons coupled to Einstein phonons and the electron-phonon entanglement content of excited states,
G. Roósz and K. Held,
Phys. Rev. B 106, 195404 (2022), DOI: 10.1103/PhysRevB.106.195404

2024
Parity-conserving Cooper-pair transport and ideal superconducting diode in planar germanium,
M. Valentini, O. Sagi, L. Baghumyan, T. de Gijsel, J. Jung, S. Calcaterra, A. Ballabio, J. Aguilera Servin, K. Aggarwal, M. Janik, T. Adletzberger, R. Seoane Souto, M. Leijnse, J. Danon, C. Schrade, E. Bakkers, D. Chrastina, G. Isella, and G. Katsaros,
Nature Communications 15, 168 (2024)

2024
Quantum Fluctuations Suppress the Critical Fields in BaCo2(AsO4)2,
S. Safari, W. Bateman-Hemphill, A. Mitra, F. Desrochers, E. Z. Zhang, L. Shafeek, A. Ferrenti, T. M. McQueen, A. Shekhter, Z. Köllö, Y. Baek Kim, B. J. Ramshaw, and K. A. Modic,
arXiv:2403.15315v1 (2024)

2024
How to identify and characterize strongly correlated topological semimetals,
D. M. Kirschbaum, M. Lužnik, G. Le Roy, and S. Paschen,
J. Phys. Mater. 7(1), 012003 (2024), DOI: 10.1088/2515-7639/ad0f30

2023
Shot noise in a strange metal,
L. Chen, D. T. Lowder, E. Bakali, A. M. Andrews, W. Schrenk, M. Waas, R. Svagera, G. Eguchi, L. Prochaska, Y. Wang, C. Setty, S. Sur, Q. Si, S. Paschen, and D. Natelson,
Science 382(6673), 907–911 (2023), DOI: 10.1126/science.abq6100

Boosting the surface conduction in a topological insulator,
M. Taupin, G. Eguchi, M. Lužnik, A. Steiger-Thirsfeld, Y. Ishida, K. Kuroda, S. Shin, A. Kimura, and S. Paschen,
Phys. Rev. B 107, 235306 (2023), DOI: 10.1103/PhysRevB.107.235306

Quantum criticality enabled by intertwined degrees of freedom,
C.-C. Liu, S. Paschen, and Q. Si,
Proceedings of the National Academy of Sciences of the United States of America, 120(30), e2300903120 (2023), DOI: 10.1073/pnas.2300903120

2024
Modulated critical currents of spin-transfer torque-induced resistance changes in NiCu/Cu multilayered nanowires,
M. Fu, R. Hartmann, J. Braun, S. Andreev, T. Pietsch, and E. Scheer,
Beilstein J. Nanotechnol. 15, 360 (2024), DOI: 3762/bjnano.15.32

Single-crystalline YIG flakes with uniaxial in-plane anisotropy and diverse crystallographic orientations,
R. Hartmann, Seema, I. Soldatov, M. Lammel, D. Lignon, X. Y. Ai, G. Kiliani, R. Schäfer, A. Erb, R. Gross, J. Boneberg, M. Müller, S. T. B. Goennenwein, E. Scheer, and A. Di Bernardo,
APL Mater. 12, 031121 (2024), DOI: 1063/5.0189993

2023
Intrinsic giant magnetoresistance due to exchange-bias-type effects at the surface of single-crystalline NiS2 nanoflakes,
R. Hartmann, M. Högen, D. Lignon, A. K. C. Tan, M. Amado, S. El-Khatib, M. Egilmez, B. Das, C. Leighton, M. Atatüre, E. Scheer, and A. Di Bernardo,
Nanoscale 15, 10277 (2023), DOI: 1039/D3NR00467H

Liquid-diffusion-limited growth of vanadium dioxide single crystals,
N. Sprinkart, D. Kazenwadel, R. Hartmann, and P. Baum,
Rev. Research 5, 013028 (2023), DOI: 10.1103/PhysRevResearch.5.013028

Nonlinear transport properties of atomic copper point contacts,
M. Strohmeier, K. Kirchberger, and E. Scheer,
Low Temp. Phys. 49, 827 (2023), DOI: 1063/10.0019693

2024
Proximity-induced gapless superconductivity in two-dimensional Rashba semiconductor in magnetic field,
S. S. Babkin, A. P. Higginbotham, M. Serbyn,
arXiv:2311.09347v2 (2024)

2023
High-Tc cuprates – story of two electronic subsystems, N. Barišić (session organizer),
05.09.2023, Gemeinsame Jahrestagung von SPS und ÖPG 2023, Basel, Switzerland

Itinerant vs. localized charges and crystal structure in cuprates, N. Barišić (invited talk),
04.08.2023, 84th Course: K. Alex Müller Workshop on Complexity in Quantum Materials (40 Years of High-Tc Erice Workshops), Erice, Italy

Experimentally Established Universal and Non-Universal Properties that Define the Physics of Cuprates, N. Barišić (invited talk),
26.06.2023, Quantum in Complex Matter, Superstripe 2023, Ischia, Italy

Optical conductivity of cuprates in a new light, N. Barišić (invited talk),
14.06.2023, 7th Conference of the Serbian Society for Ceramic Materials, Belgrade, Serbia

High-Tc cuprates – story of two electronic subsystems, N. Barišić (invited talk),
08.06.2023, Joint workshop of the project IMPULZ SUPERSPIN-IM-26 and ERA-CHAIR-project LAMatCU 2023, Bratislava, Slovakia

High-Tc cuprates – story of two electronic subsystems, N. Barišić (invited talk),
18.05.2023, The Inaugural Workshop on the Trends in Quantum Matter 2023, Notre Dame, USA

Experimentally Established Universal and Non-Universal Properties that Define the Physics of Cuprates, N. Barišić (invited talk),
08.05.2023, 8th International Conference in Superconductivity and Magnetism (ICSM 2023), Fethiye, Turkey

2023
Nickelate superconductivity – theory, K. Held (invited talk),
13.11.2023, Ringberg Symposium 2023, Rottach-Egern, Germany

Dynamical vertex calculations for nickelate superconductors, K. Held (invited talk),
20.10.2023, Workshop on Computational Approaches to Quantum Many-Body Systems 2023, Saitama, Japan

Lecture on DMFT, K. Held (invited talk),
11.10.2023, ISSP International Workshop on HIerarchical Structure and Machine Learning (HISML) 2023, Tokyo, Japan

Dynamical Vertex Approximation Approach in Strongly Correlated Electron Systems, P. Worm (invited talk),
06.03.2023, APS March Meeting 2023, Las Vegas, USA

2023
Have Majorana zero modes been observed in superconductor-semiconductor devices?, G. Katsaros (seminar talk),
20.10.2023, Atominstitut, TU Wien, Vienna
Hybrid semiconductor–superconductor devices hold great promise for realizing Majorana zero modes [1-3]. However, multiple claims of Majorana detection, based on either tunnelling or Coulomb blockade (CB) spectroscopy, remain disputed. In this talk I will introduce an experimental protocol that allows to perform both types of measurement on the same hybrid island by adjusting its charging energy via tunable junctions to the normal leads [4,5]. This method reduces ambiguities of Majorana detections by checking the consistency between CB spectroscopy and zero-bias peaks in non-blockaded transport. I will discuss the theoretical interpretation of the experimental observations in terms of low-energy, longitudinally confined island states rather than overlapping Majorana modes. The results highlight the importance of combined measurements on the same device for the identification of topological Majorana zero modes.
[1] Beenakker, C., Annu. Rev. of Condens. Matter Phys. 4, 113 (2013)
[2] Lutchyn, R. M. et al., Nat. Rev. Mater. 3, 52 (2018)
[3] Prada, E. et al., Nat. Rev. Phys. 2, 575 (2020)
[4] Valentini, M. et al., Science 373, 82 (2021)
[5] Valentini M., Borovkov, M. et al., Nature 612, 442 (2022)

Spin qubits and hybrid devices in planar Ge, G. Katsaros (invited seminar talk),
26.05.2023, ICMM, Madrid, Abstract

Hybrid devices in planar Ge, G. Katsaros (invited seminar talk),
13.04.2023, TU Delft, Delft

Invited talks at international conferences/workshops/schools

2024
Designing strongly correlated topological semimetals, S. Paschen,
07.-11.01.2024, US-German WE-Heraeus-Seminar, Engineered Quantum Materials, Physikzentrum Bad Honnef, Germany

2023
Strange metal behavior – From heavy fermion metals to topological semimetals, S. Paschen,
11.-15.12.2023, 802. WE-Heraeus-Seminar, Strange Metals in Quantum Materials and Quantum Emulators

A walk through the wonderland of heavy fermions, S. Paschen,
30.11.2023, Workshop Electron Correlations: From Basic Properties to Applications, MPI CPfS Dresden, Germany

Topological semimetals in strongly correlated systems, S. Paschen,
27.-30.11.2023, ECMetAC Days 2023, Kranjska Gora, Slovenia

Exotic states in heavy fermion compounds, S. Paschen,
12.-17.11.2023, Ringberg-Symposium Exotic States of Quantum Condensed Matter, Ringberg Castle

Extreme responses of heavy fermion systems, S. Paschen,
09.11.2023, VBFF Symposium on Extreme Quantum Materials, Rice University, Houston, USA

Correlation-driven topological semimetals, S. Paschen,
06.-08.11.2023, RCQM Workshop on Flat Bands, Strong Correlations and Topology, Rice University, Houston, USA

Strongly correlated topological semimetals, S. Paschen,
15.-18.10.2023, 797. WE-Heraeus-Seminar, Interfacing Low and High-Energy Physics with Topological Matter, Bad Honnef, Germany

Strange metal behavior in heavy fermion metals and semimetals, S. Paschen,
25.-29.09.2023, International Workshop on Quantum Materials in the Quantum Information Era, MPI PKS Dresden, Germany

Strongly correlated rare earth intermetallics, S. Paschen,
25.-27.09.2023, XV International Conference Crystal Chemistry of Intermetallic Compounds, Lviv, Ukraine (online)

New tools to decipher strange metal physics, S. Paschen,
09.-12.08.2023, 7th InterAcademy Workshop, Non-equilibrium and Meso-scale Frontiers in Quantum Many-body Physics, Monte Verita, Ascona, Switzerland

Strange metal behavior in heavy fermion compounds and beyond, S. Paschen,
24.-28.07.2023, Workshop Correlations in Novel Quantum Materials, Stuttgart, Germany

The strange metal YbRh2Si2, S. Paschen,
02.-07.07.2023, International Conference on Strongly Correlated Electron Systems (SCES23), Incheon, Korea

Topological semimetals driven by strong correlations, S. Paschen,
19.-21.04.2023, KPS Spring Meeting, D5-ap: Phonon Spin Transport Properties Pioneer Symposium I, Daejeon, Korea (online)

Weyl-Kondo semimetals – Phenomena and stabilization mechanisms, S. Paschen,
05.-10.03.2023, APS March Meeting, Session M24: Emergent Phenomena in Strongly Correlated Quantum Materials, Las Vegas, USA

Invited seminars/colloquia

2023
Correlation-driven topological semimetals, S. Paschen,
08.06.2023, Condensed Matter Seminar (CMS), Stanford University, Stanford, USA

Strange metal heavy fermion compounds – A testbed for quantum simulators and entanglement meters?, S. Paschen,
13.01.2023, ATI Seminar, Atominstitut, TU Wien, Vienna, Austria

Further presentations

2023
Thermal conductivity measurements of the quantum critical compound Ce₃Pd₂₀Si₆, G. Le Roy (poster presentation),
28.09.2023, Quantum Materials in the Quantum Information Era 2023, Dresden, Germany

2024
Current-induced switching in atomic-size contacts, M. Strohmeier (contributed talk),
25.-29.03.2024, IV International workshop on point-contact-spectroscopy, Kharkiv, Ukraine (online)

Tunneling spectroscopy on hybrid SC-FM bilayers made of non-centrosymmetric NbRe and Co, M. Strohmeier (contributed talk),
17.-22.03.2024, DPG-Frühjahrstagung der Sektion Kondensierte Materie (SKM), Berlin, Germany

Single-crystalline YIG nanoflakes with uniaxial in-plane anisotropy and various crystallographic orientations, R. Hartmann (contributed talk),
17.-22.03.2024, DPG-Frühjahrstagung der Sektion Kondensierte Materie (SKM), Berlin, Germany

2023
Combining transport measurements and scanning tunneling spectroscopy on unconventional materials, R. Fischer-Süßlin (contributed talk),
27.08.-09.09.2023, ESONN’2023 – European School on Nanosciences & Nanotechnologies, Grenoble, France

Transport and structural characterisation of the metal to insulator transition in Ca2RuO4 nanoflakes, R. Hartmann (contributed talk),
26.-31.03.2023, DPG-Frühjahrstagung der Sektion Kondensierte Materie (SKM), Dresden, Germany