Publications (32)
Visualizing the chiral anomaly in Dirac and Weyl semimetals with photoemission spectroscopy
Jan Behrends, Adolfo G. Grushin, Teemu Ojanen +1
Quantum anomalies are the breaking of a classical symmetry by quantum fluctuations. They dictate how physical systems of diverse nature, ranging from fundamental particles to cryst…
Anomalous conductance scaling in strained Weyl semimetals
Jan Behrends, Roni Ilan, Jens H. Bardarson
Magnetotransport provides key experimental signatures in Weyl semimetals. The longitudinal magnetoresistance is linked to the chiral anomaly and the transversal magnetoresistance t…
Symmetry classes, many-body zero modes, and supersymmetry in the complex Sachdev-Ye-Kitaev model
Jan Behrends, Benjamin Béri
The complex Sachdev-Ye-Kitaev (cSYK) model is a charge-conserving model of randomly interacting fermions. The interaction term can be chosen such that the model exhibits chiral sym…
Berry connection induced anomalous wave-packet dynamics in non-Hermitian systems
Navot Silberstein, Jan Behrends, Moshe Goldstein +1
Berry phases strongly affect the properties of crystalline materials, giving rise to modifications of the semiclassical equations of motion that govern wave-packet dynamics. In non…
Supersymmetry in the nonsupersymmetric Sachdev-Ye-Kitaev model
Jan Behrends, Benjamin Béri
Supersymmetry is a powerful concept in quantum many-body physics. It helps to illuminate ground state properties of complex quantum systems and gives relations between correlation…
Quantum tunneling in the presence of a topology-changing fermionic bath
Elis Roberts, Jan Behrends, Benjamin Béri
Coupling a quantum particle to a fermionic bath suppresses the particle's amplitude to tunnel, even at zero temperature. While this effect can generally be neglected for gapped bat…
Projected logical ensembles in surface codes via the random-matrix theory of quantum dots
Mircea Bejan, Jan Behrends, Max McGinley +1
Measurements underpin active quantum error correction (QEC) and have been recognized as a source of novel measurement-induced many-body phenomena. Here, we study the statistical pr…
Computing with many encoded logical qubits beyond break-even
Shival Dasu, Matthew DeCross, Andrew Y. Guo +42
High-rate quantum error correcting (QEC) codes encode many logical qubits in a given number of physical qubits, making them promising candidates for quantum computation. Implementi…
Site-selective measurement of coupled spin pairs in an organic semiconductor
Sam L. Bayliss, Leah R. Weiss, Anatol Mitioglu +14
From organic electronics to biological systems, understanding the role of intermolecular interactions between spin pairs is a key challenge. Here we show how such pairs can be sele…
Transversal magnetotransport in Weyl semimetals: Exact numerical approach
Jan Behrends, Flore K. Kunst, Björn Sbierski
Magnetotransport experiments on Weyl semimetals are essential for investigating the intriguing topological and low-energy properties of Weyl nodes. If the transport direction is pe…
Nodal-line semimetals from Weyl superlattices
Jan Behrends, Jun-Won Rhim, Shang Liu +2
The existence and topological classification of lower-dimensional Fermi surfaces is often tied to the crystal symmetries of the underlying lattice systems. Artificially engineered…
Critical non-equilibrium phases from noisy topological memories
Amir-Reza Negari, Subhayan Sahu, Jan Behrends +2
We demonstrate the existence of an extended non-equilibrium critical phase, characterized by sub-exponential decay of conditional mutual information (CMI), in the surface code subj…
Controllable bipolaron formation unveiling structural features of trap states in organic charge transport
Zichen Wang, Ilia Kulikov, Tarig Mustafa +2
Magnetic resonance methods offer a unique chance for in-depth study of conductive organic material systems, not only accounts for number of charge carriers, but also allows manipul…
Coherent error threshold for surface codes from Majorana delocalization
Florian Venn, Jan Behrends, Benjamin Béri
Statistical mechanics mappings provide key insights on quantum error correction. However, existing mappings assume incoherent noise, thus ignoring coherent errors due to, e.g., spu…
Surface codes, quantum circuits, and entanglement phases
Jan Behrends, Florian Venn, Benjamin Béri
Surface codes$\unicode{x2014}$leading candidates for quantum error correction (QEC)$\unicode{x2014}$and entanglement phases$\unicode{x2014}$a key notion for many-body quantum dynam…
Bulk-boundary correspondence from the inter-cellular Zak phase
Jun-Won Rhim, Jan Behrends, Jens H. Bardarson
The Zak phase , the generalization of the Berry phase to Bloch wave functions in solids, is often used to characterize inversion-symmetric 1D topological insulators; however, s…
Statistical mechanical mapping and maximum-likelihood thresholds for the surface code under generic single-qubit coherent errors
Jan Behrends, Benjamin Béri
The surface code, one of the leading candidates for quantum error correction, is known to protect encoded quantum information against stochastic, i.e., incoherent errors. The prote…
Sachdev-Ye-Kitaev circuits for braiding and charging Majorana zero modes
Jan Behrends, Benjamin Béri
The Sachdev-Ye-Kitaev (SYK) model is an all-to-all interacting Majorana fermion model for many-body quantum chaos and the holographic correspondence. Here we construct fermionic al…
Conductivity scaling and absence of localization in disordered nodal line semimetals
Carolina Paiva, Jan Behrends
Transport plays a key role in characterizing topological insulators and semimetals. Understanding the effect of disorder is crucial to assess the robustness of experimental signatu…
Quantum Geometric Bounds in Non-Hermitian Systems
Milosz Matraszek, Wojciech J. Jankowski, Jan Behrends
We identify quantum geometric bounds for observables in non-Hermitian systems. We find unique bounds on non-Hermitian quantum geometric tensors, generalized two-point response corr…
Direct Detection of Photoinduced Charge Transfer Complexes in Polymer:Fullerene Blends
Jan Behrends, Andreas Sperlich, Alexander Schnegg +5
We report transient electron paramagnetic resonance (trEPR) measurements with sub-microsecond time resolution performed on a P3HT:PCBM blend at low temperature. The trEPR spectrum…
The tenfold way and many-body zero modes in the Sachdev-Ye-Kitaev model
Jan Behrends, Jens H. Bardarson, Benjamin Béri
The Sachdev-Ye-Kitaev (SYK) model, in its simplest form, describes Majorana fermions with random all-to-all four-body interactions. We consider the SYK model in the framework o…
Strongly angle-dependent magnetoresistance in Weyl semimetals with long-range disorder
Jan Behrends, Jens H. Bardarson
The chiral anomaly in Weyl semimetals states that the left- and right-handed Weyl fermions, constituting the low energy description, are not individually conserved, resulting, for…
Quantum geometry of non-Hermitian systems
Jan Behrends, Roni Ilan, Moshe Goldstein
The Berry curvature characterizes one aspect of the geometry of quantum states. It materializes, among other consequences, as an anomalous velocity of wave packets. In non-Hermitia…
Room Temperature Optically and Magnetically Active Edges in Phosphorene Nanoribbons
Arjun Ashoka, Adam J. Clancy, Naitik A. Panjwani +20
Nanoribbons - nanometer wide strips of a two-dimensional material - are a unique system in condensed matter physics. They combine the exotic electronic structures of low-dimensiona…
The surface code beyond Pauli channels: Logical noise coherence, information-theoretic measures, and errorfield-double phenomenology
Jan Behrends, Benjamin Béri
We consider the surface code under errors featuring both coherent and incoherent components and study the coherence of the corresponding logical noise channel and how this impacts…
High-Spin State Dynamics and Quintet-Mediated Emission in Intramolecular Singlet Fission
Jeannine Grüne, Steph Montanaro, Thomas W. Bradbury +11
High-spin states in molecular systems hold significant interest for a wide range of applications ranging from optoelectronics to quantum information and singlet fission (SF). Quint…
Optical read and write of spin states in organic diradicals
Rituparno Chowdhury, Petri Murto, Naitik A. Panjwani +17
Optical control and read-out of the ground state spin structure has been demonstrated for defect states in crystalline semiconductors, including the diamond NV- center, and these a…
Landau levels, Bardeen polynomials and Fermi arcs in Weyl semimetals: the who's who of the chiral anomaly
Jan Behrends, Sthitadhi Roy, Michael H. Kolodrubetz +2
Condensed matter systems realizing Weyl fermions exhibit striking phenomenology derived from their topologically protected surface states as well as chiral anomalies induced by ele…
Second-Order Bulk-Boundary Correspondence in Rotationally Symmetric Topological Superconductors from Stacked Dirac Hamiltonians
Elis Roberts, Jan Behrends, Benjamin Béri
Two-dimensional second-order topological superconductors host zero-dimensional Majorana bound states at their boundaries. In this work, focusing on rotation-invariant crystalline t…
Lock-in detection for pulsed electrically detected magnetic resonance
Felix Hoehne, Lukas Dreher, Jan Behrends +7
We show that in pulsed electrically detected magnetic resonance (pEDMR) signal modulation in combination with a lock-in detection scheme can reduce the low-frequency noise level by…
The Post-Merger Magnetized Evolution of White Dwarf Binaries: The Double-Degenerate Channel of Sub-Chandrasekhar Type Ia Supernovae and the Formation of Magnetized White Dwarfs
Suoqing Ji, Robert T. Fisher, Enrique Garcia-Berro +6
Type Ia supernovae (SNe Ia) play a crucial role as standardizable cosmological candles, though the nature of their progenitors is a subject of active investigation. Recent observat…