161 citations · 2.1k across the 37 of their papers we have counts for
32 papers · 1 filter
Designing a mechanically driven spin-crossover molecular switch via organic embedding
Sumanta Bhandary, Jan M. Tomczak, Angelo Valli
Among spin-crossover complexes, Fe-porphyrin (FeP) stands out for molecular spintronic applications: An intricate, yet favourable balance between ligand fields, charge transfer, an…
Resistivity saturation in Kondo insulators
Matthias Pickem, Emanuele Maggio, Jan M. Tomczak
Resistivities of heavy-fermion insulators typically saturate below a characteristic temperature . For some, metallic surface states, potentially from a non-trivial bulk topolo…
Coulomb Engineering of two-dimensional Mott materials
Erik G. C. P. van Loon, Malte Schüler, Daniel Springer +3
Two-dimensional materials can be strongly influenced by their surroundings. A dielectric environment screens and reduces the Coulomb interaction between electrons in the two-dimens…
Topotactic hydrogen in nickelate superconductors and akin infinite-layer oxides ABO2
Liang Si, Wen Xiao, Josef Kaufmann +4
Superconducting nickelates appear to be difficult to synthesize. Since the chemical reduction of ABO3 (A: rare earth; B transition metal) with CaH2 may result in both, ABO2 and ABO…
Isoelectronic tuning of heavy fermion systems: Proposal to synthesize Ce3Sb4Pd3
Jan M. Tomczak
The study of (quantum) phase transitions in heavy-fermion compounds relies on a detailed understanding of the microscopic control parameters that induce them. While the influence o…
Realistic many-body theory of Kondo insulators: Renormalizations and fluctuations in CeBiPt
Jan M. Tomczak
Our theoretical understanding of heavy-fermion compounds mainly derives from iconic models, such as those due to Kondo or Anderson. While providing invaluable qualitative insight,…
Strain-induced tuning of the electronic Coulomb interaction in 3d transition metal oxide perovskites
Bongjae Kim, Peitao Liu, Jan M. Tomczak +1
Epitaxial strain offers an effective route to tune the physical parameters in transition metal oxides. So far, most studies have focused on the effects of strain on the bandwidths…
Thermoelectricity in correlated narrow-gap semiconductors
Jan M. Tomczak
We review many-body effects, their microscopic origin, as well as their impact onto thermoelectricity in correlated narrow-gap semiconductors. Members of this class---such as FeSi…
The AbinitioDA Project v1.0: Non-local correlations beyond and susceptibilities within dynamical mean-field theory
Anna Galler, Patrik Thunström, Josef Kaufmann +3
The ab initio extension of the dynamical vertex approximation (DA) method allows for realistic materials calculations that include non-local correlations beyond and dynamic…
Strongly correlated double Dirac fermions
Domenico Di Sante, Andreas Hausoel, Paolo Barone +3
Double Dirac fermions have recently been identified as possible quasiparticles hosted by three-dimensional crystals with particular non-symmorphic point group symmetries. Applying…
Ab initio dynamical vertex approximation
Anna Galler, Patrik Thunström, Patrik Gunacker +2
Diagrammatic extensions of dynamical mean field theory (DMFT) such as the dynamical vertex approximation (DA) allow us to include non-local correlations beyond DMFT on all lengt…
A route to room temperature ferromagnetic ultrathin SrRuO films
Liang Si, Zhicheng Zhong, Jan M. Tomczak +1
Experimental efforts to stabilize ferromagnetism in ultrathin films of transition metal oxides have so far failed, despite expectations based on density functional theory (DFT) and…
On the separability of dynamical and non-local correlations in three dimensions
T. Schäfer, A. Toschi, Jan M. Tomczak
While second-order phase transitions always cause strong non-local fluctuations, their effect on spectral properties crucially depends on the dimensionality. For the important case…
QSGW+DMFT: an electronic structure scheme for the iron pnictides and beyond
Jan M. Tomczak
While in strongly correlated materials one often focuses on local electronic correlations, the influence of non-local exchange and correlation effects beyond band-theory can be per…
Protected Fe valence in quasi-two dimensional -FeSi
W. Miiller, J. M. Tomczak, J. W. Simonson +3
We report the first comprehensive study of the high temperature form (-phase) of iron disilicide. Measurements of the magnetic susceptibility, magnetization, heat capacity and r…
Dynamical correlations and screened exchange on the experimental bench: spectral properties of the cobalt pnictide BaCo2As2
Ambroise van Roekeghem, Thomas Ayral, Jan M. Tomczak +7
Understanding the Fermi surface and low-energy excitations of iron or cobalt pnictides is crucial for assessing electronic instabilities such as magnetic or superconducting states.…
Electronic correlations in FeGa and the effect of hole doping on its magnetic properties
M. B. Gamza, J. M. Tomczak, C. Brown +3
We investigate signatures of electronic correlations in the narrow-gap semiconductor FeGa by means of electrical resistivity and thermodynamic measurements performed on single…
Asymmetric band widening by screened exchange competing with local correlations in SrVO3: new surprises on an old compound from combined GW and dynamical mean field theory GW+DMFT
Jan M. Tomczak, Michele Casula, Takashi Miyake +1
The very first dynamical implementation of the combined GW and dynamical mean field scheme "GW+DMFT" for a real material was achieved recently [J.M. Tomczak et al., Europhys. Lett.…
Electronics with correlated oxides: SrVO/SrTiO as a Mott transistor
Zhicheng Zhong, Markus Wallerberger, Jan M. Tomczak +5
We employ density functional theory plus dynamical mean field theory and identify the physical origin of why two layers of SrVO on a SrTiO substrate are insulating: the thi…
Highly Dispersive Electron Relaxation and Colossal Thermoelectricity in the Correlated Semiconductor FeSb
Peijie Sun, Wenhu Xu, Jan M. Tomczak +4
We show that the colossal thermoelectric power, , observed in the correlated semiconductor FeSb below 30\,K is accompanied by a huge Nernst coefficient and magneto…
Rare-Earth vs. Heavy Metal Pigments and their Colors from First Principles
Jan M. Tomczak, L. V. Pourovskii, L. Vaugier +2
Many inorganic pigments contain heavy metals hazardous to health and environment. Much attention has been devoted to the quest for non-toxic alternatives based on rare-earth elemen…
Thermopower of the Correlated Narrow Gap Semiconductor FeSi and Comparison to RuSi
Jan M. Tomczak, K. Haule, G. Kotliar
Iron based narrow gap semiconductors such as FeSi, FeSb2, or FeGa3 have received a lot of attention because they exhibit a large thermopower, as well as striking similarities to he…
Combined GW and dynamical mean field theory: Dynamical screening effects in transition metal oxides
Jan M. Tomczak, Michele Casula, Takashi Miyake +2
We present the first dynamical implementation of the combined GW and dynamical mean field scheme ("GW+DMFT") for first principles calculations of the electronic properties of corre…
Many-body effects in iron pnictides and chalcogenides -- non-local vs dynamic origin of effective masses
Jan M. Tomczak, M. van Schilfgaarde, G. Kotliar
We apply the quasi-particle self-consistent GW (QSGW) approximation to some of the iron pnictide and chalcogenide superconductors. We compute Fermi surfaces and density of states,…