188 citations · 1.5k across the 41 of their papers we have counts for
41 papers
Monte Carlo Studies of Twisted Bilayer Graphene: Strain and Thermal Fluctuations
Johannes S. Hofmann, Patrick Ledwith, Ashvin Vishwanath +2
We study the phase diagram of twisted bilayer graphene at charge neutrality as a function of twist angle , uniaxial heterostrain , and temperature using sign-pr…
Superconductivity, charge density wave, and supersolidity in flat bands with tunable quantum metric
Johannes S. Hofmann, Erez Berg, Debanjan Chowdhury
Predicting the fate of an interacting system in the limit where the electronic bandwidth is quenched is often highly non-trivial. The complex interplay between interactions and qua…
Nonrelativistic Conformal Invariance in Mesoscopic Two-Dimensional Fermi Gases
Viktor Bekassy, Johannes Hofmann
Two-dimensional Fermi gases with universal short-range interactions are known to exhibit a quantum anomaly, where a classical scale and conformal invariance is broken by quantum ef…
Analytic approach to transport in superconducting junctions with arbitrary carrier density
F. Setiawan, Johannes Hofmann
Particle transport across Josephson junctions is commonly described using a simplifying approximation (often called the Andreev approximation), which assumes that excitations are f…
Corrections to reaction-diffusion dynamics above the upper critical dimension
Johannes Hofmann
Reaction-diffusion models are common in many areas of statistical physics, where they describe the late-time dynamics of chemical reactions. Using a Bose gas representation, which…
Fermionic Monte Carlo study of a realistic model of twisted bilayer graphene
Johannes S. Hofmann, Eslam Khalaf, Ashvin Vishwanath +2
The rich phenomenology of twisted bilayer graphene (TBG) near the magic angle is believed to arise from electron correlations in topological flat bands. An unbiased approach to thi…
Electromagnetic response of composite Dirac fermions in the half-filled Landau level
Johannes Hofmann
An effective field theory of composite Dirac fermions was proposed by Son [Phys. Rev. X 5, 031027 (2015)] as a theory of the half-filled Landau level with explicit particle-hole sy…
Hydrodynamics of a superfluid smectic
Johannes Hofmann, Wilhelm Zwerger
We determine the hydrodynamic modes of the superfluid analog of a smectic-A phase in liquid crystals, i.e., a state in which both gauge invariance and translational invariance alon…
Specific Heat of a Quantum Critical Metal
Ori Grossman, Johannes S. Hofmann, Tobias Holder +1
We investigate the specific heat, , near an Ising nematic quantum critical point (QCP), using sign problem-free quantum Monte Carlo simulations. Cooling towards the QCP, we find…
Universal relations for dipolar quantum gases
Johannes Hofmann, Wilhelm Zwerger
We establish that two-dimensional dipolar quantum gases admit a universal description, i.e., their thermodynamic properties are independent of details of the interaction at short d…
Formation of silicon nanocrystals in silicon carbide using flash lamp annealing
C. Weiss, M. Schnabel, S. Prucnal +5
During the formation of Si nanocrystals (Si NC) in SiC layers via solid-phase crystallization, the unintended formation of nanocrystalline SiC reduces the minority carr…
A search for correlation-induced adiabatic paths between distinct topological insulators
Johannes S. Hofmann, Fakher F. Assaad, Raquel Queiroz +1
Correlations in topological states of matter provide a rich phenomenology, including a reduction in the topological classification of the interacting system compared to its non-int…
Probing embedded topological modes in bulk-like GeTe-SbTe heterostructures
Hisao Nakamura, Johannes Hofmann, Nobuki Inoue +5
The interface between topological and normal insulators hosts metallic states that appear due to the change in band topology. While these topological states at a surface, i.e., a t…
Superconductivity, pseudogap, and phase separation in topological flat bands: a quantum Monte Carlo study
Johannes S. Hofmann, Erez Berg, Debanjan Chowdhury
We study a two-dimensional model of an isolated narrow topological band at partial filling with local attractive interactions. Numerically exact quantum Monte Carlo calculations sh…
High-temperature expansion of the viscosity in interacting quantum gases
Johannes Hofmann
We compute the frequency-dependent shear and bulk viscosity spectral functions of an interacting Fermi gas in a quantum virial expansion up to second quadratic order in the fugacit…
Quantum oscillations in Dirac magnetoplasmons
Johannes Hofmann
The plasmon frequency in standard electron gases with a parabolic single-particle dispersion is a purely classical quantity that is not sensitive to electron interactions or the eq…
Tunable surface plasmons in Weyl semimetals TaAs and NbAs
Gennaro Chiarello, Johannes Hofmann, Zhilin Li +5
By means of high-resolution electron energy loss spectroscopy, we investigate the low-energy excitation spectrum of transition-metal monopnictides hosting Weyl fermions. We observe…
Kondo Breakdown via Fractionalization in a Frustrated Kondo Lattice Model
Johannes S. Hofmann, Fakher F. Assaad, Tarun Grover
We consider Dirac electrons on the honeycomb lattice Kondo coupled to spin-1/2 degrees of freedom on the kagome lattice. The interactions between the spins are chosen along the lin…
Collective modes of an imbalanced unitary Fermi gas
Johannes Hofmann, Frédéric Chevy, Olga Goulko +1
We study theoretically the collective mode spectrum of a strongly imbalanced two-component unitary Fermi gas in a cigar-shaped trap, where the minority species forms a gas of polar…
Mesoscopic pairing without superconductivity
Johannes Hofmann
We discuss pairing signatures in mesoscopic nanowires with variable attractive pairing interaction. Depending on wire length, density, and interaction strength, these systems reali…
The ALF (Algorithms for Lattice Fermions) project release 1.0. Documentation for the auxiliary field quantum Monte Carlo code
Martin Bercx, Florian Goth, Johannes S. Hofmann +1
The Algorithms for Lattice Fermions package provides a general code for the finite temperature auxiliary field quantum Monte Carlo algorithm. The code is engineered to be able to s…
Spontaneous particle-hole symmetry breaking of correlated fermions on the Lieb lattice
Martin Bercx, Johannes S. Hofmann, Fakher F. Assaad +1
We study spinless fermions with nearest-neighbor repulsive interactions (- model) on the two-dimensional three-band Lieb lattice. At half-filling, the free electronic band st…
Deep inelastic scattering on ultracold gases
Johannes Hofmann, Wilhelm Zwerger
We discuss Bragg scattering on both Bose and Fermi gases with strong short-range interactions in the deep inelastic regime of large wave vector transfer , where the dynamic stru…
Surface plasmon polaritons in topological Weyl semimetals
Johannes Hofmann, Sankar Das Sarma
We consider theoretically surface plasmon polaritons in Weyl semimetals. These materials contain pairs of band touching points - Weyl nodes - with a chiral topological charge, whic…