News

Editors' Suggestion: Strong support  for  spin-fluctuations mediating superconductivity in nickelates!
12 June 2024

We compare the spin-fluctuation spectrum behind these calculations to resonant inelastic x-ray scattering experiments. The overall agreement is good. This independent cross validation of the strength of spin fluctuations strongly supports the scenario, advanced by D⁢Γ⁢A, that spin fluctuations are the mediator of the superconductivity observed in nickelates.

Phys. Rev. B 109, 235126 (2024).

"Correlations, Topology, and Entanglement"
TYC mini-workshop @ King's: 30 May 2024
6 March 2024

Registration has opened for our (free) mini-workshop featuring talks by Giorgio Sangiovanni and Giovanni Sordi. For details see here.

Talk at CCQ's DMFT-QE Symposium
8 February 2024

A video of my recent talk Simulating Correlation Effect in Quasi-2D Materials is now available for viewing.

Editor's Suggestion: Localized f-electron magnetism in the semimetal Ce3Bi4Au3
12 December 2023

Results of a fruitful collaboration with Priscila Rosa's group at Los Alamos National Laboratory.

New paper: LK-99 is a Mott or charge transfer insulator
6 November 2023

The first paper I was ever involved in, where the publishing process took longer than the actual research (by a large margin!) has now been published as J. Phys.: Condens. Matter 36, 065601 (2024).

New paper: Inducing metal-insulator transitions with a changing dielectric environment
6 July 2023

With Erik van Loon et al, we demonstrate that a Mott insulator-to-metal transition can be triggered in a quasi-2D system, when a dielectric is moved into proximity, opening possibilities for sensors and switches. npj 2D Materials and Applications 7, 47 (2023)

Visitor: Léo Gaspard
5 June 2023

Welcome to Léo Gaspard @gaspard_leo who will be with us at King's for two months to study the screening of magnetic moments, and more...

New paper: transport in polyacetylene molecular wires
15 May 2023

With Angelo Valli, we study transport properties of the Su-Schrieffer-Heeger model, comparing the Landauer and Kubo formalisms.

J Comput Electron (2023)

New paper: Palladates might be good superconductors
20 April 2023

Comprehensive simulations of the Hubbard model reveal that cuprates are not optimal for superconductivity. We speculate that palladates are.

Phys. Rev. Lett. 130, 166002 (2023)

Senior Lecturer at King's College London
4 January 2023

I am happy to announce that I have joined King's College London as a Senior Lecturer. My research group is part of the Theory & Simulation of Condensed Matter group in Department of Physics. While retaining a presence at TU Wien, my research activities will henceforth be primarily based in London.

To begin with, I have an opening for a PhD position at King's!

New paper: Shedding light on a correlated pigment
27 October 2022

Distortions of the manganese bipyramidal coordination help circumventing atomic selection rules, allow for dipolar d−d transitions, and result in the blue color of the material.

Phys. Rev. Materials 6, 105003 (2022)

Joint Austrian-French project "RECORD" will be funded by FWF & ANR
1 October 2022

Cyril Martins (Université Toulouse III, France) and I (TU Wien, Austria) are thrilled to announce that our joint project RECORD on disorder and correlations will receive funding from the Austrian Science Fund and the Agence Nationale de la Recherche, starting 1.4.2023. Look out for PhD and postdoc openings!

New paper: Binaural fluctuation diagnostics
3 October 2022

When and why do fluctuations lead to large non-local renormalizations? Our new paper provides insight by linking fluctuation diagnostics to spectral properties.

Phys. Rev. Research 4, 033253 (2022)

LinReTraCe: The Linear Response Transport Centre
14 June 2022

Our open-source transport code has gone live!

arxiv:2206.06097

https://github.com/linretrace 

Prototypical many-body signatures in transport properties of semiconductors
23 February 2022

The interplay of charge gap and scattering rate lead to the emergence of characteristic temperature scales in transport observables (beyond Boltzmann theory).
Phys. Rev. B 105, 085139 (2022)

Toward Functionalized Ultrathin Oxide Films: The Impact of Surface Apical Oxygen

Unavoidable oxygen adatoms strongly influence properties of ultrathin oxide films.

https://onlinelibrary.wiley.com/doi/full/10.1002/aelm.202101006

Thermopower boosted by enhanced phonon-drag in LaAlO3 / LaNiO3 / LaAlO3 heterostructure

Large thermopowers driven by heavy electrons coupling to phonons that leak through an interface in a LaAlO3/LaNiO3/LaAlO3 heterostructure.

https://pubs.acs.org/doi/10.1021/acs.nanolett.1c03143

Breaking of thermopower-conductivity trade-off in LaTiO3 thin films

Stabilizing transition metal-oxide thin films near their Mott transition through substrate-engineering may boost the thermoelectric power-factor. onlinelibrary.wiley.com/doi/full/10.1002/advs.202102097

See press release at www.titech.ac.jp/english/news/2021/062112

Resistivity Saturation in Kondo Insulators

We establish a new mechanism for the low-temperature saturation of the resistivity in Kondo insulators and other narrow-gap semiconductors. www.nature.com/articles/s42005-021-00723-z 

Welcome Andriy to the group!

Andriy Smolyanyuk has joined the group this week! He obtained his PhD at TU Graz and worked at Duke University as a postdoc before joining us in Vienna. He will develop a toolkit for band interpolation and topology.

How to design a spin-crossover molecular switch via organic embedding

Combining density functional theory with many-body techniques, we show experimentally feasible tensile strain to trigger a low- to high-spin crossover in an iron porphyrin molecule contacted by graphene nano-ribbons. Concomitantly, the current through the device toggles by over an order of magnitude, adding a fully planar mechanical current-switch unit to existing molecular spintronics. 

DOI: 10.1039/D1NA00407G.

Nonlocal fluctuations and ordering instabilities in ultra-thin oxide films

Our many-body calculations reveal a cornucopia of nonlocal fluctuations in an ultra-thin oxide film associated with ferromagnetic, (in)commensurate antiferromagnetic, and stripe and checkerboard orbital ordering instabilities. Identifying how the film geometry controls the crystal-field splitting, we elucidate the ensuing phases through the lens of the orbital degrees of freedom.  DOI: 10.1103/PhysRevB.104.024307.

Anisotropy of electronic correlations:
On the applicability of local theories to layered materials 

Besides chemical constituents, it is the lattice geometry that controls the most important material properties. In many interesting compounds, the arrangement of elements leads to pronounced anisotropies, which reflect into a varying degree of quasi-two-dimensionality of their low-energy excitations. Here, we (1) classify important families of correlated materials according to the anisotropy of their ab initio electronic (band) structure; (2) we investigate for a progressively larger anisotropy the nonlocality of many-body renormalizations in the Hubbard model.  DOI: 10.1103/PhysRevB.103.045121.

Emanuele received FWF Stand-Alone Project fund

We are happy to announce that Emanuele (together with co-Project Lead, Jan) has received a FWF Stand-Alone Project fund for 'BandITT - Band Interpolation and Topology Toolkit'! This will provide €396K in funding over 3 years to develop a computer code that allows us to systematically explore materials.