Publications

P. M. Lenggenhager, X. Liu, T. Neupert, and T. Bzdušek
arXiv
 – 
Published
22 Apr 2021

We show that pairs of triple points in systems with negligible spin-orbit coupling (three-fold momentum-space band structure degeneracies along high-symmetry lines) facilitate higher-topology. Our main result is a universal bulk-hinge correspondence of such pairs to fractional quantized jumps of the hinge charge as a function of the hinge-momentum. For the special case of \(\mathcal{P}\mathcal{T}\)-symmetric crystalline solids we further find that triple points are characterized by monople charges. We illustrate the derived phenomena on material examples using first-principles calculations.

P. M. Lenggenhager, X. Liu, T. Neupert, and T. Bzdušek
arXiv
 – 
Published
22 Apr 2021

We show that pairs of triple points in systems with negligible spin-orbit coupling (three-fold momentum-space band structure degeneracies along high-symmetry lines) facilitate higher-topology. Our main result is a universal bulk-hinge correspondence of such pairs to fractional quantized jumps of the hinge charge as a function of the hinge-momentum. For the special case of \(\mathcal{P}\mathcal{T}\)-symmetric crystalline solids we further find that triple points are characterized by monople charges. We illustrate the derived phenomena on material examples using first-principles calculations.

P. M. Lenggenhager, X. Liu, S. S. Tsirkin, T. Neupert, and T. Bzdušek
Phys. Rev. B 103, L121101 (2021)
 – 
Published
01 Mar 2021

We classify three-fold momentum-space band structure degeneracies (triple points) occurring along high-symmetry lines of \(\mathcal{P}\mathcal{T}\)-symmetric crystalline solids with negligible spin-orbit coupling. By employing the recently discovered non-Abelian band topology, we argue that a rotation-symmetry-breaking strain transforms a certain class of triple points into multi-band nodal links. We propose material candidates and study the consequences of this phenomenon.

P. M. Lenggenhager, X. Liu, S. S. Tsirkin, T. Neupert, and T. Bzdušek
Phys. Rev. B 103, L121101 (2021)
 – 
Published
01 Mar 2021

We classify three-fold momentum-space band structure degeneracies (triple points) occurring along high-symmetry lines of \(\mathcal{P}\mathcal{T}\)-symmetric crystalline solids with negligible spin-orbit coupling. By employing the recently discovered non-Abelian band topology, we argue that a rotation-symmetry-breaking strain transforms a certain class of triple points into multi-band nodal links. We propose material candidates and study the consequences of this phenomenon.

P. M. Lenggenhager, D. E. Gökmen, Z. Ringel, S. D. Huber, and M. Koch-Janusz
Phys. Rev. X 10, 011037 (2020)
 – 
Published
14 Feb 2020

We consider a recently introduced real-space renormalization group (RG) algorithm which is based on maximizing real-space mutual information (RSMI). Based on general proofs and detailed studies of arbitrary coarse-grainings of the Ising chain, we argue that maximizing RSMI minimizes the range of interactions and, for disordered systems, correlations in the disorder distribution of the coarse-grained system.

P. M. Lenggenhager, D. E. Gökmen, Z. Ringel, S. D. Huber, and M. Koch-Janusz
Phys. Rev. X 10, 011037 (2020)
 – 
Published
14 Feb 2020

We consider a recently introduced real-space renormalization group (RG) algorithm which is based on maximizing real-space mutual information (RSMI). Based on general proofs and detailed studies of arbitrary coarse-grainings of the Ising chain, we argue that maximizing RSMI minimizes the range of interactions and, for disordered systems, correlations in the disorder distribution of the coarse-grained system.