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A connection between quantum dot Dirac operators and $\overline\partial$-Robin Laplacians in the context of shape optimization problems
Joaquim Duran, Albert Mas, Tom\'as Sanz-Perela
https://arxiv.org/abs/2507.18698

A connection between quantum dot Dirac operators and $\overline\partial$-Robin Laplacians in the context of shape optimization problems
This work addresses Faber-Krahn-type inequalities for quantum dot Dirac operators with nonnegative mass on bounded domains in $\mathbb{R}^2$. We show that this family of inequalities is equivalent to a family of Faber-Krahn-type inequalities for $\overline\partial$-Robin Laplacians. Thanks to this, we prove them in the case of simply connected domains for quantum dot boundary conditions asymptotically close to zigzag boundary conditions. Finally, we also study the case of negative mass.

Tailoring Magnetic Properties of Zigzag Structured Thin Films via Interface Engineering and Columnar Nano-structuring
Sharanjeet Singh, Manisha Priyadarsini, Anup Kumar Bera, Smritiparna Ghosh, Varimalla R. Reddy, Sarathlal Koyiloth Vayalil, Benedikt Sochor, Dileep Kumar
https://arxiv.org/abs/2506.19577

Tailoring Magnetic Properties of Zigzag Structured Thin Films via Interface Engineering and Columnar Nano-structuring
We report the emergence of a novel interface-induced shape anisotropy component in zigzag-structured thin films fabricated via Sequential Oblique Angle Deposition (S-OAD). In this study, we systematically investigate cobalt (Co) and Co2FeAl (CFA) thin films by varying column length, number of bilayers, and magneto-crystalline anisotropy (MCA) to explore how structural modulation affects magnetic behavior. Using magneto-optical Kerr effect (MOKE) measurements in conjunction with synchrotron-base…

Exploring Low-Dimensional Magnetism in Cobalt Vanadates, ${A}$CoV$_{2}$O$_{7}$~(${A}$~=~Ca, Sr) : Crystal Growth and Magnetic Properties of Effective Spin-1/2 Zigzag Chains
Anzar Ali, Guratinder Kaur, Arvind Maurya, Isha, Kathrin K\"uster, Ulrich Starke, Pascal Puphal, Arvind Kumar Yogi, Masahiko Isobe
https://arxiv.org/ab…

Exploring Low-Dimensional Magnetism in Cobalt Vanadates, ${A}$CoV$_{2}$O$_{7}$~(${A}$~=~Ca, Sr) : Crystal Growth and Magnetic Properties of Effective Spin-1/2 Zigzag Chains
We report the successful growth of high-quality single crystals of \ACVO, a quasi-one-dimensional zigzag chain compound containing Co$^{2+}$ ions, using the optical floating zone method. The crystal growth was stabilized under high-pressure argon-oxygen gas with slow growth rates, overcoming challenges associated with the incongruent melting behavior of this material. X-ray diffraction confirms the zigzag arrangement of Co$^{2+}$ ions, forming a quasi-one-dimensional chain structure. Magnetic s…

Folding of quadrilaterals, zigzags, and Arnold-Liouville integrability
Anton Izosimov
https://arxiv.org/abs/2507.17549 https://arxiv.org/pdf/2507.17549

Folding of quadrilaterals, zigzags, and Arnold-Liouville integrability
We put Darboux's porism on folding of quadrilaterals, as well as closely related Bottema's zigzag porism, in the context of Arnold-Liouville integrability.

Graphene Nanoribbons as a Majorana Platform
Ruize Ma, Michele Pizzochero, Gaurav Chaudhary
https://arxiv.org/abs/2506.14999 https://a…

Graphene Nanoribbons as a Majorana Platform
Graphene nanoribbons support a range of electronic phases that can be controlled via external stimuli. Zigzag-edged graphene nanoribbons (ZGNRs), in particular, exhibit an antiferromagnetic insulating ground state that transitions to a half-metallic phase under a transverse electric field or when embedded inside hexagonal Boron Nitride. Here, we consider a simple model of a heterostructure of a ZGNR with an Ising superconductor and show that, the Ising superconductor with a parent s-wave spin-s…

Zigzag antiferromagnets in the SU(3) Hubbard model on the square lattice
Stijn V. Kleijweg, Philippe Corboz
https://arxiv.org/abs/2506.14703 https://

Zigzag antiferromagnets in the SU(3) Hubbard model on the square lattice
SU(N) Hubbard models exhibit a rich variety of phases, which may be realized through quantum simulation with ultracold atomic gases in optical lattices. In this work we study the Mott insulating phases of the SU(3) Hubbard model at 1/3-filling using infinite projected entangled-pair states, optimized with both imaginary time evolution and variational optimization. In the limit of strong interactions we reproduce the antiferromagnetic 3-sublattice ordered state previously identified in the SU(3)…

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Probing the band structure of the strongly correlated antiferromagnet NiPS3 across its phase transition
Benjamin Pestka, Biplab Bhattacharyya, Milosz Rybak, Jeff Strasdas, Adam K. Budniak, Adi Harchol, Marcus Liebmann, Niklas Leuth, Honey Boban, Vitaliy Feyer, Iulia Cojocariu, Daniel Baranowski, Simone Mearini, Lutz Waldecker, Bernd Beschoten, Christoph Stampfer, Yaron Amouyal, Lukasz Plucinski, Efrat Lifshitz, Krzysztof Wohlfeld, Magdalena Birowska, Markus Morgenstern

Probing the band structure of the strongly correlated antiferromagnet NiPS3 across its phase transition
NiPS3 is an exfoliable van-der-Waals intralayer antiferromagnet with zigzag-type spin arrangement. It is distinct from other TMPS3 (TM: transition metal) materials by optical excitations into a strongly correlated state that is tied to the magnetic properties. However, the related, fundamental band structure across the antiferromagnetic phase transition has not been probed yet. Here, we use angular-resolved photoelectron spectroscopy with μm resolution in combination with DFT+U calculations fo…

Quantum Monte Carlo study of artificial triangular graphene quantum dots
E. Bulut Kul, G\"okhan \"Oztarhan, M. N. \c{C}{\i}nar, A. D. G\"u\c{c}l\"u
https://arxiv.org/abs/2506.08621

Quantum Monte Carlo study of artificial triangular graphene quantum dots
We investigate the magnetic phases of triangular graphene quantum dots (TGQDs) with zigzag edges using variational and quantum Monte Carlo methods. These systems serve as quantum simulators for bipartite lattices with broken sublattice symmetry, providing a platform to study the extended Hubbard model's emergent magnetic phenomena, including Lieb's magnetism at half-filling, edge depolarization upon single-electron addition, and Nagaoka ferromagnetism. Our non-perturbative quantum…

Quantum Hall Andreev Conversion in Graphene Nanostructures
Alexey Bondarev, William H. Klein, Harold U. Baranger
https://arxiv.org/abs/2507.02114 https://

Quantum Hall Andreev Conversion in Graphene Nanostructures
We study Andreev conversion in clean nanostructures containing an interface between graphene in the quantum Hall (QH) state and a superconductor, focusing on the lowest Landau level. First, several graphene nanostructures formed from zigzag edges with sharp corners are considered using a tight-binding model. We find the scattering state for an electron impinging on the interface from the upstream QH edge state, together with the probability of it exiting as a hole in the downstream QH edge stat…

This https://arxiv.org/abs/2504.13197 has been replaced.
initial toot: https://mastoxiv.page/@arX…

Superzone gap formation induced by ferroic orders
We demonstrate that a superzone gap, typically associated with antiferroic ordering, can also emerge from ferroic orders in systems with sublattice degrees of freedom. By analyzing a $p$-orbital tight-binding model on a zigzag chain, we show that a Su--Schrieffer--Heeger-type gap is induced by ferroquadrupolar or ferromagnetic order or by applying an external magnetic field.

Instantons and topological order in two-leg electron ladders: A universality class
S. -R. Eric Yang, Hyun Cheol Lee, Hoang-Anh Le, In-Hwan Lee
https://arxiv.org/abs/2505.24130

Instantons and topological order in two-leg electron ladders: A universality class
Our numerical study of the disordered Hubbard model with nearest-neighbor hopping shows that a two-leg electron ladder has a finite topological entanglement entropy in the regime where the density of states exhibits an exponentially decaying gap. The value of the topological entanglement entropy suggests that two-leg ladders belong to the same universality class as graphene zigzag nanoribbons, despite several structural differences. A Shankar-Witten-type bosonization Lagrangian with disorder ca…