Mesoscale and Nanoscale Physics · Cross-listed from cond-mat.soft
Tilt control of coverage heterogeneity for hard spherocylinders locked on a sphere
Jonathan Washburn, Hartmut Löwen and Elshad Allahyarov
We study hard spherocylinders on a sphere with axes rigidly locked to a tangential director field at fixed angle $\tilt$ to the meridian, necessarily singular at the poles. Three lengths set the problem: the rod length $\Lrod$, the diameter $\Drod$, and the host radius $\Rsph$. Monte Carlo simulations across fifteen geometries and four coverages give two main results for the polar marginal, the azimuthal average of rod-center density. First, the tilt is a continuous handle on the width of the depleted region that packing induces around each singularity. Under meridian locking it is set principally by the rod length; turning the director toward the latitude contracts it substantially, the contraction being spent well before latitude locking. Second, how uniform the polar marginal can be made is limited by geometry, not tilt. The smallest variance on the sampled grid follows a power law in $\Lrod^{2}/(\Rsph\Drod)$, which measures how far a straight rod's ends stand off the curved surface in rod diameters, with an effective exponent between $1.1$ and $1.3$. Long rods on small hosts cannot be made uniform at any sampled tilt; the remedy is
geometric, not orientational. The polar marginal is equator-heavy almost everywhere, inverting only at high coverage and tilt; meridian locking is the least uniform choice, and the variance-minimizing tilt usually lies in a sampled band from $31.7^{\circ}$ to $55^{\circ}$. The golden-ratio tilt $\arctan(1/\phigold)$ is one of those angles: a
benchmark, not one the model selects. Both results describe the infinitely locked athermal ensemble.
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Mesoscale and Nanoscale Physics
A Simple Regularization of the Smooth Quantum Hydrodynamic Model
Carl L. Gardner
A simple regularization of the smooth
quantum hydrodynamic model equations to prevent an unstable growing mode is proposed. The regularization involves replacing the spatial derivative of the electron density on the right-hand side of the momentum conservation equation by using the classical Boltzmann distribution for electron density. Time-dependent simulations of the resonant tunneling diode to steady state using this regularization are presented, which show realistic negative differential resistance (the experimental signal of
quantum resonance) and hysteresis in the current-voltage curve. The simulations are in good agreement with fully
quantum mechanical simulations of the resonant tunneling diode.
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Mesoscale and Nanoscale Physics · Cross-listed from math-ph
Hartree–Fock coercivity for twisted bilayer graphene
Kevin D. Stubbs and Maciej Zworski
We study the minimisers of the Hartree–Fock functional for flat bands in the chiral model of twisted bilayer
graphene introduced by Tarnopolsky, Kruchkov, and Vishwanath. Our model is a continuous version of the discrete model considered by Becker, Lin and Stubbs in previous works and the first result is a direct analogue of main
theorems of those papers: at half filling of the flat band of multiplicity two, there are exactly two minimisers, obtained by occupying either one of the two sub-bands. (A more general version of this result, stressing its topological origins, was presented in Appendix A.8 of the Lecture Notes by Tao-Zworski.) The new contribution is the strict coercivity of the Hessian of the Hartree–Fock functional at the two minimisers. It is a consequence of the difference between the Chern numbers of the component bands and can be optimistically considered as a soft version of a “spectral gap”.
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Mesoscale and Nanoscale Physics
Quantum encoding of structured light into in-plane topological spin textures
Pavel A. Vorobyev, Daichi Kurebayashi and Oleg A. Tretiakov
Structured light offers a powerful means of controlling light-matter interactions through multiple tunable optical degrees of freedom. Using micromagnetic simulations, we investigate the nucleation of asymmetric bimerons and antibimerons by pulsed Laguerre-Gaussian optical
vortices in chiral ferromagnetic thin films with $C_{nv}$ and $D_{2d}$
symmetries, respectively. For optical
vortices with orbital angular momentum (OAM) $|m|=1$, circularly polarized beams deterministically nucleate a single bimeron or antibimeron via the interplay of
spin angular momentum, OAM, and
magnetic chirality, whereas linearly polarized beams produce textures whose topological charge directly follows the OAM ($Q=m$). Optical
vortices with OAM $|m|>1$ nucleate clusters and other configurations composed of multiple
spin textures, whose morphology and topological charge depend sensitively on the optical
quantum numbers and pulse parameters. These findings reveal a route to
topology-selective writing through the encoding of optical
quantum numbers into distinct in-plane topological
magnetic states.
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Mesoscale and Nanoscale Physics · Cross-listed from cond-mat.mtrl-sci
Spectrally Programmable Spin-Polarized Photocurrents in WSe$_2$-NiPS$_3$ Magnetic van der Waals Heterostructures
Rajesh Kumar Yadav, Michal Poplinger, Adi Levi et al. (+6 more)
Efficient generation and control of
spin-polarized currents in
semiconductors remain central challenges for
spin-based electronics, particularly due to impedance mismatch and the reliance on
magnetic fields or ferromagnetic contacts. Here, we introduce a materials platform for spectrally programmable
spin transport based on a van der Waals
heterostructure combining the antiferromagnetic
semiconductor NiPS$_3$ with WSe$_2$. In a p-n diode architecture, circularly polarized excitation produces pronounced photoconductive resonances with
spin polarization reaching 80% near the Neel temperature and persisting at 30% at room temperature. Remarkably, selected spectral bands retain their polarization sign across the
magnetic phase transition, evidencing robust, spectrally protected
spin-polarized current generation. Polarization-resolved photogalvanic measurements reveal a dominant circular injection-current mechanism, confirming
spin-polarized carrier transport. First-principles calculations show that an applied electric field induces interfacial hybridization and
spin-layer locking, giving rise to localized
symmetry breaking and enhanced optical absorption while preserving global time-reversal
symmetry. These results establish spectral tuning of excitation as a new control knob for
spin transport, enabling
spin-current generation without
magnetic fields or polarization switching. Our findings position
magnetic van der Waals
heterostructures as a versatile platform for opto-spintronic functionality and spectrally programmable spintronic devices.
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All authors Rajesh Kumar Yadav, Michal Poplinger, Adi Levi, Adi Harchol, Nirman Chakraborty, Thomas Brumme, Thomas Heine, Efrat Lifshitz, Doron Naveh
Mesoscale and Nanoscale Physics · Cross-listed from cond-mat.str-el
Large scale theoretical investigation of the phase diagram of twisted bilayer MoTe$_2$ at fractional fillings: agreements and contradictions with current experiments
Heqiu Li, Jiabin Yu, Xiaodong Xu et al. (+2 more)
We present a comprehensive exact-diagonalization study of interaction-driven phases in twisted bilayer MoTe$_2$ across experimentally relevant twist angles ($2.13^\circ$–$4^\circ$) and hole fillings. Using continuum-model moiré bands, we compare the one-band-per-valley (1BPV) projection with a two-band-per-valley (2BPV) calculation that includes interaction-driven band mixing, and we
benchmark both the widely used first-harmonic continuum model and a parameter-free DFT “fitting-free” model. At odd-denominator fillings, the 2BPV calculation reproduces the experimentally observed hierarchy of fractional Chern
insulators (FCIs) around $\theta\approx 3.7^\circ$, including robust incompressible states at $\nu=-2/3$, $-3/5$, and $-4/7$ while correctly finding the absence of an FCI at $\nu=-3/7$, and it favors a charge density wave ground state at $\nu=-1/3$ over the FCI. At half filling $\nu=-1/2$, the 1BPV calculation exhibits clear composite Fermi
liquid (CFL) signatures, whereas the band mixing in 2BPV calculations destabilizes the CFL ground state. Finally, motivated by the Landau-level analogy at $\theta\approx 2.13^\circ$, we test the proposed non-abelian Pfaffian state at $\nu=-3/2$ in the fully-polarized
spin sector but find no evidence for this state within the models and parameters studied. Our results establish a unified numerical
benchmark for correlated and topological phases in twisted bilayer MoTe$_2$ and clarify where multi-band physics is essential for a quantitative comparison with experiments.
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All authors Heqiu Li, Jiabin Yu, Xiaodong Xu, B. Andrei Bernevig, N. Regnault
Mesoscale and Nanoscale Physics · Cross-listed from cond-mat.str-el
Flux-induced Aharonov-Bohm Oscillation in the Tunneling Spectroscopy of Kitaev Spin Liquids
Wen-Han Kao and Elio J. König
Identifying emergent flux excitations and signatures of their mutual statistics with itinerant Majorana
fermions remains a central challenge in Kitaev
spin liquids. We show that an isolated $\pi$ flux imprints an intrinsic Aharonov-Bohm-like interference pattern on the charge-neutral Majorana continuum. Spatially resolved scanning tunneling microscopy with inelastic electron tunneling spectroscopy (STM-IETS) probes this oscillation in the local dynamical
spin response as a function of both bias voltage and tip-flux separation, reflecting the $\pi$ phase acquired by Majorana trajectories encircling the flux. We show that large-scale exact diagonalization of the Kitaev honeycomb model and a complementary low-energy continuum theory yield consistent radial oscillations. These results provide a finite-energy, spatially resolved tunneling signature of a preexisting flux and a diagnostic of
fermion-flux mutual statistics without requiring manipulation of individual anyons in the Kitaev
spin liquid.
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Mesoscale and Nanoscale Physics
Quaternionic Hermitian Band Geometry in Four Dimensions: Realization on $S^4$ and Obstruction on $T^4$
Dongju Hwang, Minjae Yu and Gil Young Cho
We establish a realization-obstruction dichotomy for quaternionic Hermitian band geometry in four-dimensional parameter spaces: the minimal-charge lowest Landau level on $S^{4}$ provides a global realization, whereas an everywhere nondegenerate saturated realization induced by a single occupied quaternionic band is obstructed on $T^{4}$. An antiunitary
symmetry $\mathcal{J}$ satisfying $\mathcal{J}^{2}=-1$ makes the occupied doublet a quaternionic band. Within this setting, we formulate the quaternionic Wirtinger inequality as a band-
geometric bound involving the
quantum metric and the second Chern density. At every nondegenerate saturation point, the canonical geometry of the quaternionic projective space pulls back to a compatible quaternionic structure on the parameter space; if these conditions hold everywhere, the parameter space acquires quaternionic Hermitian band geometry. On $S^{4}$, we express the minimal-charge states as quaternionic Perelomov coherent states and establish everywhere nondegenerate saturation, thereby realizing quaternionic Hermitian band geometry. On $T^{4}$, by contrast, a minimal four-band system saturates the inequality everywhere, but
topology forces the
quantum metric to become degenerate somewhere, obstructing a globally induced quaternionic structure. An explicit
lattice Dirac
Hamiltonian exhibits this obstruction. Adding unoccupied bands cannot remove this obstruction when the inequality is saturated everywhere, since the image of any nondegenerate saturated projector remains confined to a fixed $\mathbb{H}P^{1}$. These results provide a
symmetry-aware framework for non-Abelian band geometry and show how parameter-space
topology constrains the global realization of quaternionic Hermitian band geometry.
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Mesoscale and Nanoscale Physics · Cross-listed from cond-mat.mtrl-sci
The principle of detailed balance between electrons and phonons in presence of excitonic effects
Alberto Guandalini, Giovanni Caldarelli, Francesco Mauri et al. (+1 more)
Based on a many-body formulation, we derive an electron-
phonon coupling including excitonic effects that preserves thermodynamic detailed balance between electronic and phononic scattering processes. We start from the microscopic electron-
nucleus Hamiltonian, expand around the Born-Oppenheimer
equilibrium geometry, and construct an effective action for the electronic and phononic propagators. From the same effective action, we derive both electronic and phononic self-energies in terms of a nonlocal vertex $\mathcal G^{\textrm{s}}$ including excitonic effects, which generalizes the usual local interaction vertex $g^{\textrm{s}}$. When electrons and
phonons are well-defined quasiparticles in the screened-exchange approximation and $\mathcal G^{\textrm{s}}$ is taken in its static limit, both self-energies reduce to Fermi-golden-rule expressions containing the same $\mathcal G^{\textrm{s}}$, thereby ensuring detailed balance. As an application, we compute electronic and phononic linewidths in
graphene and illustrate this common-vertex construction. We analyze the competition between the reduced scattering phase space induced by the screened-exchange band structure and the enhancement of the electron-
phonon vertex due to excitonic effects, finding that the vertex enhancement can compensate for and overcome the phase-space reduction in both electronic and phononic linewidths.
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All authors Alberto Guandalini, Giovanni Caldarelli, Francesco Mauri, Francesco Macheda
Mesoscale and Nanoscale Physics · Cross-listed from quant-ph
Quantum-Geometric Length Scale for Long-distance Squeezing in Bosonic Bogoliubov Systems
Sonu Verma, Sangmo Cheon, Myung-Joong Hwang et al. (+1 more)
Multimode squeezing is a key resource for continuous-variable
quantum technologies, but its spatial range in bosonic
lattices is usually tied to dispersive propagation. Here we show that parametric pairing can create an exactly flat Bogoliubov band spanned by compact Bogoliubov generators, while producing phase-sensitive anomalous correlations and sub-
vacuum collective-mode squeezing that extend far beyond their finite support. Each compact generator mixes annihilation and creation operators, thereby encoding the Bogoliubov squeezing structure, and neighboring translated generators can have nonzero commutator overlap. Enforcing canonical bosonic commutation relations therefore requires spatially extended linear combinations of these translated compact generators, which define the canonical Bogoliubov modes. The squeezing transformation of these modes varies with momentum and is quantified by the squeezing-sector symplectic
quantum metric. A complex-momentum singularity of the analytically continued canonical Bogoliubov modes sets both the anomalous-correlation decay length and the momentum-space width of this metric, defining an intrinsic
quantum-
geometric length scale. This singularity can be tuned continuously while preserving exact flatness, thereby controlling the spatial range of correlations and squeezing. Away from exact flatness, long-distance correlations persist through multiple decay channels, while modes localized by defects and dimerized boundaries provide complementary probes of the underlying
quantum geometry. In the weak-damping limit, the same
quantum-
geometric length scale can be extracted from frequency-filtered two-port correlations. Our results establish the
quantum geometry of canonical Bogoliubov modes as a mechanism for spatially extended
quantum resources arising from compact Bogoliubov generators.
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All authors Sonu Verma, Sangmo Cheon, Myung-Joong Hwang, Moon Jip Park
Mesoscale and Nanoscale Physics · Cross-listed from cond-mat.mtrl-sci
Absence of lateral domain wall mobility in Zn1-xMgxO thin films
Jack Eckstein, Kyle P. Kelley, William Prudnick et al. (+4 more)
Polarization reversal in ferroelectrics arises from the coupled processes of domain nucleation and subsequent growth, yet the governing mechanisms differ fundamentally between classical perovskite oxides and emerging wurtzite ferroelectrics. While switching in perovskites is typically governed by mobile domain walls whose field-driven propagation dominates macroscopic kinetics, here we show that polarization reversal in wurtzite Zn1-xMgxO proceeds through a qualitatively different pathway. Using scanning oscillator microscopy, in combination with point pulse-imaging methods, we directly map local switching events and domain wall responses, revealing that domain walls in Zn1-xMgxO exhibit negligible lateral mobility (sub 10nm) and that polarization reversal proceeds predominantly through the nucleation of vertically extended columnar filaments with a lateral size on the order of the grains. This nucleation-controlled switching contrasts sharply with the growth-mediated dynamics characteristic of perovskite ferroelectrics and explains the abrupt, spatially localized switching behavior observed in wurtzite systems. These results establish nucleation-dominated filamentary reversal as a defining switching mechanism in Zn1-xMgxO and point towards the need for further studies to understand correlation lengths and nucleation processes across a range of grain sizes.
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All authors Jack Eckstein, Kyle P. Kelley, William Prudnick, Jon-Paul Maria, Stephen Jesse, Neus Domingo, Rama K. Vasudevan
Mesoscale and Nanoscale Physics
Quantum Geometry Driven Optical Responses in 1T-MX$_2$ Monolayers: A Symmetry-Constrained Slater-Koster Tight-Binding Approach
Bikram Baruah, Snehasish Nandy and Subhasis Panda
Centrosymmetric 1T-MX$_2$ monolayers(MLs) have attracted considerable
attention owing to their intriguing transport properties and potential technological applications arising from the interplay among
quantum geometry, electronic band structure, and band-gap characteristics. Despite this rich physics, a comprehensive microscopic tight-binding(TB) description that simultaneously captures these properties remains insufficiently established, while first-principles approaches can be computationally demanding for systematic investigations across different materials and perturbations. Here, we develop a transferable eleven-band Slater-Koster TB description of ML 1T-MX$_2$ TMDs and use it to establish a connection among their microscopic electronic structure,
quantum geometry, and optical response. The model is constructed in an orthogonal orbital basis from the
crystal geometry and
symmetry-constrained SK parameters, with material-specific parametrizations obtained from DFT calculations for ML ZrS$_2$ and HfS$_2$. The resulting geometry-based
Hamiltonian accurately describes the low-energy electronic structures and provides a natural framework for extending the analysis to the broader isostructural 1T-MX$_2$ family. We find that the pristine MLs possess a finite
quantum metric, with the dominant contribution concentrated in the two highest occupied bands owing to the small near-gap energy separation and strong metal-chalcogen $p$-$d$ hybridization. Furthermore, we verify the interband $f$-sum rule, which directly relates the integrated optical spectral weight to the Brillouin-zone-averaged
quantum metric. Our results establish optical spectral weight as an experimentally accessible probe of the
quantum geometry of occupied Bloch states and provide a unified microscopic framework for connecting electronic structure,
quantum geometry, and measurable optical responses across the 1T-MX$_2$ family.
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Mesoscale and Nanoscale Physics
Enhanced intrinsic spin-orbit driving of a Loss-DiVincenzo qubit near the spin-valley hotspot in Si/SiGe
Alexander Willmes, Max Oberländer, Max Beer et al. (+7 more)
In most Si/SiGe-based
spin qubit implementations, high-fidelity single-
qubit gates are achieved using micromagnets, which enable the use of electric
spin dipole resonance via synthetic
spin-orbit coupling (s-SOC). In contrast, intrinsic
spin-orbit coupling (i-SOC) in silicon is generally considered to be weak. However, in Si/SiGe
heterostructures, theory predicts a substantial enhancement when the Zeeman splitting approaches the valley splitting if
symmetry is reduced by an imperfect interface. Here, we demonstrate a Si/SiGe Loss-DiVincenzo
qubit driven by i-SOC close to this so-called
spin-valley hotspot. In particular, we characterize the Rabi frequency as a function of the energy detuning from the hotspot by sweeping both the
magnetic field and
quantum dot position. We observe the predicted enhancement of the Rabi frequency near the hotspot, but also find an asymmetry that deviates from existing theoretical models as well as distortions of the Chevron patterns near the hotspot. While we achieve an average single-
qubit Clifford fidelity of 98.6 %, the strong variability of the valley splitting may impede the use of i-SOC-based control as a scalable operational strategy; understanding its effect is nevertheless important for reproducible high-fidelity control. Our results provide an empirical basis for refining current theoretical models of
spin-valley physics in Si/SiGe
heterostructures.
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All authors Alexander Willmes, Max Oberländer, Max Beer, Denny Dütz, Jhih-Sian Tu, Stefan Trellenkamp, Marco Lisker, Felix Reichmann, Lars R. Schreiber, Hendrik Bluhm
Mesoscale and Nanoscale Physics
Electrostatic control of Li+ density and transport rate in double-gated van der Waals devices
E. Hoenig, X. Zhang, C. Li et al. (+7 more)
Ion transport in crystalline hosts is controlled by an applied potential that simultaneously sets ionic distribution and transport rate, restricting operation to a one-dimensional control space. Here we show that the transport rate of Li+ ions in double-gated van der Waals devices can be modulated while the system occupies fixed ionic-density states. We measure the ionic current along the van der Waals interfaces between hexagonal boron nitride and
graphene or MoS2 while simultaneously monitoring the in-plane electronic response. The ionic current exhibits pronounced hysteresis, with plateaus marking discrete ionic-density states balanced by electronic charge, while an independently tuneable electrochemical-potential drop controls the ionic transport rate. The devices sustain over 1,000 switching cycles and function as hybrid ionic-electronic transistors capable of logic operations and
memory retention, with ON/OFF ratios exceeding two orders of magnitude. This work demonstrates a two-dimensional control space for ions intercalated in layered materials.
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All authors E. Hoenig, X. Zhang, C. Li, J. Tong, G. Chen, L. Chen, D. Domaretskiy, D. R. da Costa, F. M. Peeters, M. Lozada-Hidalgo
Mesoscale and Nanoscale Physics · Cross-listed from quant-ph
What do position and time mean in the quantum wavefunction?
Mustafa Bakr, Zichi Zhang and Margot Stakenborg
The notation $\psi(x,t)$ is among the first pieces of
quantum mechanics that students learn. It is also among the easiest to over-interpret. Because $x$ and $t$ occur as arguments of the same function, students may ask whether they have the same mathematical status. They may also ask whether $\psi(t)$ should require a generalized bra $\bra{t}$ in the same way that $\psi(x)=\braket{x}{\psi}$ is often written. A related question is whether the absence of a universal time operator follows simply from Pauli's argument. These questions mix several structures that are usually introduced in different parts of the curriculum. We present a unified pedagogical treatment built around two maps hidden in $\psi(x,t)$. Time
evolution selects a state along a trajectory in
Hilbert space. A spectral representation then maps that state to amplitudes labelled by outcomes of a chosen observable. We formulate the position representation without generalized eigenkets. We recover Dirac's $\ket{x}$ notation as a controlled continuum shorthand and use a finite-grid limit to show where delta normalization enters. We distinguish background coordinates, translation parameters, observables, spectral labels, and physical records. We also clarify the Stone-
theorem analogy, compare prescribed-time position measurements with arrival-time measurements, state what the strong form of Pauli's argument excludes, and exhibit an exactly solvable boundary case in which a canonical self-adjoint time observable exists.
Spin,
circuit-QED, and optical-clock examples provide experimentally grounded checks. The aim is not a new interpretation of time. It is a reusable teaching framework for separating mathematical role from notation.
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Mesoscale and Nanoscale Physics · Cross-listed from cond-mat.mtrl-sci
Displacement-field-driven reconstruction of low energy transport in few-layer PtSe2
Xiao Liu, Yaroslav Zhumagulov, Yuang Jie et al. (+9 more)
In layered
semiconductors, a perpendicular displacement field generates an interlayer potential difference that competes with interlayer hybridization, modifying both the band gap and the finite-density electronic states that carry current. Resolving this interplay requires a material lying close to the
semiconductor-to-semimetal transition, where moderate electric fields can strongly reshape the low-energy electronic structure. Here, we investigate displacement-field-driven transport in dual-gated semiconducting PtSe2, whose pronounced thickness-dependent electronic structure provides access to this low-band-gap regime. Unlike thinner layers, the displacement-field response is strong in six-layer PtSe2, which lies at the verge of the
semiconductor-to-semimetal crossover with only a small residual transport gap. Even weak displacement fields rapidly suppress this residual gap near charge neutrality, driving the system toward a band-overlap regime. At the same time, the conductivity decreases in the heavily hole-doped regime, demonstrating that the displacement field modifies not only the gap but also the conducting valence-band states. Fixed-relaxation-time Wannier transport calculations reproduce both responses, showing that they originate from field-induced band overlap together with reconstruction of the valence-band dispersion. These results establish finite-density transport as a sensitive probe of displacement-field-driven electronic structure reconstruction and extend electrical control beyond conventional band-gap engineering.
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All authors Xiao Liu, Yaroslav Zhumagulov, Yuang Jie, Ahmet Enes Bozcali, Johan Felisaz, Qi Zhang, Oldvrich Cicvarek, Kenji Watanabe, Takashi Taniguchi, Zdeněk Sofer, Oleg V. Yazyev, Ahmet Avsar
Mesoscale and Nanoscale Physics · Cross-listed from cond-mat.mtrl-sci
Discovery of New Zintl Films and Nanowires Grown by Topotaxy Conversion of III-V Semiconductors
Man Suk Song, Lothar Houben, Jean Souza et al. (+8 more)
Zintl phases draw broad interest for their diverse structural,
magnetic, thermoelectric, topological and optical properties. Recently, Zintl Eu$_3$In$_2$As$_4$ and Eu$_5$In$_2$As$_6$ nanowires with
axion magneto-
topology have been synthesized by molecular beam epitaxy via topotactic conversion of InAs wurtzite and zincblende nanowires. Here we extend this methodology, demonstrating that topotaxial mutual-exchange growth applies not only to a broader set of III-V
semiconductors beyond InAs but also to three-dimensional substrates whose surfaces are converted into Zintl thin films, as well as to nanowires. We report the growth of two new compounds: Eu$_5$Ga$_2$As$_6$ thin films converted from GaAs substrates, and Eu$_5$Al$_2$As$_6$ thin films from AlAs films. We also convert GaAs nanowires of both wurtzite and zincblende structures into Eu$_5$Ga$_2$As$_6$ nanowires. Though the stoichiometry is the same as in the previously reported Eu$_5$In$_2$As$_6$ case, microscopy and diffraction reveal a single-phase Pnma
symmetry group rather than Pbam, highlighting
symmetry-guided topotactic pathways to new Zintl frameworks. The compounds host an intricate
magnetic phase diagram with three
magnetic transitions, including two distinct antiferromagnetic orders and a canted antiferromagnetic phase that evolves into another antiferromagnetic phase under applied field through a
spin-flop transition. Ab initio calculations predict that both Zintls are
semiconductors with gaps of 0.79 eV in Eu$_5$Ga$_2$As$_6$ and 0.90 eV in Eu$_5$Al$_2$As$_6$. The lower
symmetry and increased structural complexity suggest suppressed
lattice thermal conductivity, pointing to thermoelectric potential alongside prospects in spintronics and detector technologies. These results give an epitaxy-compatible route for discovering and integrating
magnetic Zintl thin films and nanowires directly from relevant III-V
semiconductors.
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All authors Man Suk Song, Lothar Houben, Jean Souza, Edanel Fishbein, Moshe Haim, Ambikesh Gupta, Yufei Zhao, Anna-Eden Kossoy, Binghai Yan, Haim Beidenkopf, Hadas Shtrikman