arXiv subjects

Zhi-Cheng Wang

Publications and source records attributed to Zhi-Cheng Wang.

At least 19 recordsLinked to original sources

arXiv2026

Transition fronts of combustion reaction-diffusion equations in domains with multiple cylindrical branches

This paper is concerned with propagation dynamics for combustion reaction-diffusion equations in domains with multiple cylindrical branches. We first establish the existence and uniqueness of a time-increasing entire solution behaving like planar traveling fronts in some branches and converging to $0$ in the remaining part of the domain as $t\to-\infty$. Under the assumption of complete propagation, we then show that this entire solution propagates into the other branches in the form of planar traveling fronts (up to finite shifts) and converges to $1$ elsewhere as $t\to+\infty$. In particular, it is proved that this entire solution is a transition front connecting $0$ and $1$, whose global mean speed coincides with the planar wave speed. By assuming complete propagation for front-like solutions originating from single branch, we further prove that every transition front connecting $0$ and $1$ propagates completely. Moreover, we show that the global mean speed is independent of the choice of transition front. Namely, all transition fronts connecting $0$ and $1$ share the same global mean speed.Finally, we provide two sufficient geometric conditions under which the complete propagation assumptions are satisfied.

math.AP↗

arXiv2026

Precise propagation profile for some monostable free boundary problems in time-periodic media

We consider reaction-diffusion equations of the form \begin{equation*} u_t - d u_{xx} = f(t,u), \quad t>0,\ \ x \in [g(t), h(t)], \end{equation*} where $f(t,u)$ is periodic in $t$ and monostable in $u$, and the interval $[g(t), h(t)]$ represents the one dimensional population range of a species with density $u(t,x)$ at time $t$ and spatial location $x$. The free boundaries $x=g(t)$ and $x=h(t)$ evolve subject to a ``preferred population density" condition at the habitat edges. Analogous to the traveling wave solutions in the corresponding Cauchy problem, semi-wave solutions play a fundamental role in understanding the propagation phenomena governed by the free boundary problem here. But in contrast to the Cauchy problem, where the KPP condition plays a subtle role in the precise approximation of its solution (with compactly supported initial function) by the traveling wave solution with minimal speed, here we prove the existence and uniqueness of a semi-wave in a general monostable setting, and obtain a precise description of the convergence of the solution toward the semi-wave as time goes to infinity, where the KPP condition plays no special role. Previously, such a sharp result was proved for a free boundary model only when $f$ is autonomous ($f=f(u)$, see \cite{D} or \cite{DL15} for a related free boundary model), or a less precise result was obtained in the time-periodic case under an extra strong KPP condition on $f$ (see \cite{MDW}, or \cite{DGP} for a related free boundary model). This work appears to be the first to prove the sharp convergence result for a general monostable free boundary problem in a heterogeneous environment, and we believe the methods developed here should have applications to related free boundary problems in heterogeneous media with nonlinearities more general than those of KPP type.

math.AP↗

arXiv2025

Design, synthesis, and physical properties of the intergrowth compound Eu$_2$CuZn$_2$As$_3$

The rational combination of existing magnetic topological compounds presents a promising route for designing new topological materials. We report the synthesis and comprehensive characterization of the layered quaternary intergrowth compound Eu$_2$CuZn$_2$As$_3$, which combines structural units of two known magnetic topological materials, EuCuAs and EuZn$_2$As$_2$. Eu$_2$CuZn$_2$As$_3$ exhibits an antiferromagnetic ground state with successive magnetic transitions: quasi-two-dimensional ordering at $T_\mathrm{M} = 29.3$\,K, long-range antiferromagnetic ordering at $T_\mathrm{N} = 19$\,K, and spin-reorientation at $T_\mathrm{SR} = 16.3$\,K. The stepwise magnetic transitions manifest as plateau-like anomalies in the heat capacity. These transitions originate from multiple superexchange pathways and periodic variation of interplane Eu-Eu distances in the intergrowth structure. Charge transport shows a pronounced resistivity increase above $T_\mathrm{N}$ followed by minimal change below the ordering temperature. Magnetic fields rapidly suppress this resistivity rise, yielding significant negative magnetoresistance. Remarkably, Eu$_2$CuZn$_2$As$_3$ inherits the nonlinear anomalous Hall effect characteristic of its parent compounds. Energy evaluations of collinear spin configurations reveal a lowest-energy state with ferromagnetic coupling between Eu planes in EuCuAs units while maintaining antiferromagnetic coupling within EuZn$_2$As$_2$ units. The corresponding electronic structure displays potentially topologically nontrivial features. Our work demonstrates the efficacy of structural hybridization for discovering novel magnetic topological materials and establishes a general strategy for materials discovery.

cond-mat.mtrl-sci↗

arXiv2025

Interplay of magnetic ordering and charge transport in a distorted ScAl$_3$C$_3$-type GdZn$_3$As$_3$

We present the synthesis and characterization of GdZn$_3$As$_3$, a previously unreported variant of the $RM_3X_3$ family ($R$ = lanthanides; $M$ = Zn, Cd; $X$ = P, As), prepared in both single-crystal and polycrystalline forms. Unlike other $RM_3X_3$ compounds that crystallize in undistorted hexagonal structures, GdZn$_3$As$_3$ adopts a distorted ScAl$_3$C$_3$-type orthorhombic structure with $Cmcm$ space group. Magnetic measurements demonstrate that GdZn$_3$As$_3$ undergoes a ferromagnetic transition at the Curie temperature ($T_{\mathrm{C}}$) of 6.3~K, which is unique among known $RM_3X_3$ materials. This magnetic transition is further confirmed by specific heat and electrical resistivity measurements. GdZn$_3$As$_3$ displays metallic behavior with a pronounced resistivity peak near $T_{\mathrm{C}}$, which is strongly suppressed by magnetic fields, leading to significant negative magnetoresistance. Hall effect measurements reveal a low carrier density and a clear nonlinear anomalous Hall effect in GdZn$_3$As$_3$. Furthermore, both specific heat and resistivity data suggest the presence of additional magnetic transition(s) below $T_{\mathrm{C}}$, requiring further investigation. These results demonstrate that GdZn$_3$As$_3$ possesses distinct structural, magnetic, and electronic transport properties within the $RM_3X_3$ family, establishing it as an exceptional platform for investigating competing magnetic interactions in low-carrier-density rare-earth triangular-lattice systems.

cond-mat.mtrl-sci↗

arXiv2025

Structural design and multiple magnetic orderings of the intergrowth compound Eu$_2$CuMn$_2$P$_3$

We report the design, synthesis, crystal structure, and physical properties of a layered intergrowth compound, Eu$_2$CuMn$_2$P$_3$. The structure of Eu$_2$CuMn$_2$P$_3$ features an alternating arrangement of hexagonal EuCuP block layers and trigonal EuMn$_2$P$_2$ block layers, interconnected through shared Eu planes. This structural hybridization leads to multiple magnetic orderings in Eu$_2$CuMn$_2$P$_3$: weak antiferromagnetic (AFM) ordering of Mn at $T_\mathrm{N}^\mathrm{Mn}$ = 80 K, AFM ordering of Eu at $T_\mathrm{N}^\mathrm{Eu}$ = 29 K, a spin-reorientation transition at $T_\mathrm{SR}$ = 14.5 K, and weak ferromagnetism below $T_\mathrm{N}^\mathrm{Mn}$. The spin configurations at different temperature regions were discussed based on the calculations of magnetic energies for various collinear arrangements. Resistivity measurements reveal a pronounced transition peak at $T_\mathrm{N}^\mathrm{Eu}$, which is suppressed in the presence of a magnetic field, resulting in a significant negative magnetoresistance effect. The computed semimetallic band structure, characterized by a small density of states at the Fermi level, aligns well with experimental observations. The successful synthesis of Eu$_2$CuMn$_2$P$_3$ and its fascinating magnetic properties highlight the effectiveness of our block-layer design strategy. By assembling magnetic block layers of compounds with compatible crystal symmetries and closely matched lattice parameters, this approach opens exciting avenues for discovering layered materials with unique magnetic behaviors.

cond-mat.mtrl-sci↗

arXiv2024

Unusual magnetic and transport properties in the Zintl phase Eu$_{11}$Zn$_6$As$_{12}$

Narrow-gap rare-earth Zintl phases frequently exhibit fascinating physical phenomena due to their various crystal structures, complex magnetic properties, and tunable transport behaviors. Here we report the synthesis, magnetic, thermodynamic, and transport properties of a Eu-containing Zintl arsenide, Eu$_{11}$Zn$_6$As$_{12}$, which consists of infinite chains of Eu cations and anionic frameworks constructed from corner-sharing ZnAs$_4$ tetrahedra. Eu$_{11}$Zn$_6$As$_{12}$ exhibits complicated magnetic behavior owing to intricate exchange interactions mediated by the discrete anionic fragments. Two long-range magnetic transitions at 22 K ($T_\mathrm{N}$) and 9 K ($T^*$), as well as exceptionally strong ferromagnetic fluctuations around 29 K ($T_\mathrm{F}$), are indicated by the susceptibility, heat capacity and resistivity measurements. Besides, Eu$_{11}$Zn$_6$As$_{12}$ displays metallic behavior, attributable to the hole carriers doped by slight Eu vacancies or the mixed valence of Eu$^{2+}$ and Eu$^{3+}$. A prominent resistivity peak occurs around $T_\mathrm{N}$, which is rapidly suppressed by the applied field, leading to a prominent negative magnetoresistance effect. A resistivity hysteresis is observed below 5 K, caused by a small net ferromagnetic component. Our study presents the distinct magnetic and transport properties of Eu$_{11}$Zn$_6$As$_{12}$, and further experiments are required to elucidate the origin of these novel behaviors. Moreover, our findings demonstrate that Eu-based Zintl phases are a fertile ground to study the interplay between magnetism and charge transport.

cond-mat.mtrl-sci↗

arXiv2024

Colossal magnetoresistance from spin-polarized polarons in an Ising system

Recent experiments suggest a new paradigm towards novel colossal magnetoresistance (CMR) in a family of materials EuM$_2$X$_2$(M=Cd, In, Zn; X=P, As), distinct from the traditional avenues involving Kondo-RKKY crossovers, magnetic phase transitions with structural distortions, or topological phase transitions. Here, we use angle-resolved photoemission spectroscopy (ARPES) and density functional theory (DFT) calculations to explore their origin, particularly focusing on EuCd$_2$P$_2$. While the low-energy spectral weight royally tracks that of the resistivity anomaly near the temperature with maximum magnetoresistance (T$_{MR}$) as expected from transport-spectroscopy correspondence, the spectra are completely incoherent and strongly suppressed with no hint of a Landau quasiparticle. Using systematic material and temperature dependence investigation complemented by theory, we attribute this non-quasiparticle caricature to the strong presence of entangled magnetic and lattice interactions, a characteristic enabled by the $p$-$f$ mixing. Given the known presence of ferromagnetic clusters, this naturally points to the origin of CMR being the scattering of spin-polarized polarons at the boundaries of ferromagnetic clusters. These results are not only illuminating to investigate the strong correlations and topology in EuCd$_2$X$_2$ family, but, in a broader view, exemplify how multiple cooperative interactions can give rise to extraordinary behaviors in condensed matter systems.

cond-mat.str-el↗

arXiv2024

Recent advances in understanding and manipulating magnetic and electronic properties of Eu$M_2X_2$ ($M$ = Zn, Cd; $X$ = P, As)

Over the past five years, significant progress has been made in understanding the magnetism and electronic properties of CaAl$_2$Si$_2$-type Eu$M_2X_2$ ($M$ = Zn, Cd; $X$ = P, As) compounds. Prior theoretical work and experimental studies suggested that EuCd$_2$As$_2$ had the potential to host rich topological phases, particularly an ideal magnetic Weyl semimetal state when the spins are polarized along the c axis. However, this perspective is challenged by recent experiments utilizing samples featuring ultra-low carrier densities, as well as meticulous calculations employing various approaches. Nonetheless, the Eu$M_2X_2$ family still exhibit numerous novel properties that remain to be satisfactorily explained, such as the giant nonlinear anomalous Hall effect and the colossal magnetoresistance effect. Moreover, Eu$M_2X_2$ compounds can be transformed from semiconducting antiferromagnets to metallic ferromagnets by introducing a small number of carriers or applying external pressure, and a further increase in the ferromagnetic transition temperature can be achieved by reducing the unit cell volume. These features make the Eu$M_2X_2$ family a fertile platform for studying the interplay between magnetism and charge transport, and an excellent candidate for applications in spintronics. This paper presents a comprehensive review of the magnetic and transport behaviors of Eu$M_2X_2$ compounds with varying carrier densities, as well as the current insights into these characteristics. An outlook for future research opportunities is also provided.

cond-mat.mtrl-sci↗

arXiv2024

Enhanced Magnetization by Defect-Assisted Exciton Recombination in Atomically Thin CrCl$_3$

Two dimensional (2D) semiconductors present unique opportunities to intertwine optical and magnetic functionalities and to tune these performances through defects and dopants. Here, we integrate exciton pumping into a quantum sensing protocol on nitrogen-vacancy centers in diamond to image the optically-induced transient stray fields in few-layer, antiferromagnetic CrCl$_3$. We discover that exciton recombination enhances the in-plane magnetization of the CrCl$_3$ layers, with a predominant effect in the surface monolayers. Concomitantly, time-resolved photoluminescence measurements reveal that nonradiative exciton recombination intensifies in atomically thin CrCl$_3$ with tightly localized, nearly dipole-forbidden excitons and amplified surface-to-volume ratio. Supported by experiments under controlled surface exposure and density functional theory calculations, we interpret the magnetically enhanced state to result from a defect-assisted Auger recombination that optically activates electron transfer between water vapor related surface impurities and the spin-polarized conduction band. Our work validates defect engineering as a route to enhance intrinsic magnetism in single magnetic layers and opens a novel experimental platform for studying optically-induced, transient magnetism in condensed matter systems.

cond-mat.mtrl-sci↗

arXiv2024

Manipulating magnetism and transport properties of EuCd$_2$P$_2$ with a low carrier concentration

Materials that exhibit strongly coupled magnetic order and electronic properties are crucial for both fundamental research and technological applications. However, finding a material that not only shows remarkable magnetoresistive responses but also has an easily tunable ground state remains a challenge. Here, we report successful manipulation of the magnetic and transport properties of EuCd$_2$P$_2$, which is transformed from an A-type antiferromagnet ($T_\mathrm{N}$ = 11 K) exhibiting colossal magnetoresistance into a ferromagnet ($T_\mathrm{C}$ = 47 K) with metallic behavior. The dramatic alteration results from a low hole concentration of $10^{19}$ cm$^{-3}$ induced by changing the growth conditions. Electronic structure and total energy calculations confirm the tunability of magnetism with a small carrier concentration for EuCd$_2$P$_2$. It is feasible to switch between the magnetic states by using field-effect to control the carrier density, thereby changing the magneto-electronic response. The controllable magnetism and electrical transport of EuCd$_2$P$_2$ make it a potential candidate for spintronics.

cond-mat.mtrl-sci↗

arXiv2024

Carrier-induced transition from antiferromagnetic insulator to ferromagnetic metal in the layered phosphide EuZn$_2$P$_2$

EuZn$_2$P$_2$ was reported to be an insulating antiferromagnet with $T_\mathrm{N}$ of 23.5 K. In this study, single crystals of EuZn$_2$P$_2$ exhibiting metallic behavior and a ferromagnetic order of 72 K ($T_\mathrm{C}$) are successfully synthesized via a salt flux method. The presence of hole carriers induced by the Eu vacancies in the lattice is found to be crucial for the drastic changes in magnetism and electrical transport. The carriers mediate the interlayer ferromagnetic interaction, and the coupling strength is directly related to $T_\mathrm{C}$, as evidenced by the linear dependence of $T_\mathrm{C}$ and the fitted Curie-Weiss temperatures on the Eu-layer distances for ferromagnetic Eu$M_2X_2$ ($M$ = Zn, Cd; $X$ = P, As). The ferromagnetic EuZn$_2$P$_2$ shows conspicuous negative magnetoresistance (MR) near $T_\mathrm{C}$, owing to strong magnetic scattering. The MR behavior is consistent with the Majumdar-Littlewood model, indicating that the MR can be enhanced by decreasing the carrier density. Our findings suggest that Eu$M_2X_2$ has highly tunable magnetism and charge transport, making it a promising material family for potential applications in spintronics.

cond-mat.mtrl-sci↗

arXiv2023

Absence of superconductivity in electron-doped chromium pnictides ThCrAsN$_{1-x}$O$_x$

Theoretical studies predicted possible superconductivity in electron-doped chromium pnictides isostructural to their iron counterparts. Here, we report the synthesis and characterization of a new ZrCuSiAs-type Cr-based compound ThCrAsN, as well as its oxygen-doped variants. All samples of ThCrAsN$_{1-x}$O$_x$ show metallic conduction, but no superconductivity is observed above 30 mK even though the oxygen substitution reaches 75\%. The magnetic structure of ThCrAsN is determined to be G-type antiferromagnetic by magnetization measurements and first-principles calculations jointly. The calculations also indicate that the in-plane Cr--Cr direct interaction of ThCrAsN is robust against the heavy electron doping. The calculated density of states of the orbital occupations of Cr for ThCrAs(N,O) is strongly spin-polarized. Our results suggest the similarities between chromium pnictides and iron-based superconductors shouldn't be overestimated.

cond-mat.supr-con↗

arXiv2023

Extreme sensitivity of the magnetic ground-state to halide composition in FeCl$_{3-x}$Br$_x$

Mixed halide chemistry has recently been utilized to tune the intrinsic magnetic properties of transition-metal halides $-$ one of the largest families of magnetic van der Waals materials. Prior studies have shown that the strength of exchange interactions, hence the critical temperature, can be tuned smoothly with halide composition for a given ground-state. Here we show that the ground-state itself can be altered by a small change of halide composition leading to a quantum phase transition in FeCl$_{3-x}$Br$_x$. Specifically, we find a three-fold jump in the Néel temperature and a sign change in the Weiss temperature at $x= 0.08$ corresponding to only $3\%$ bromine doping. Using neutron scattering, we reveal a change of the ground-state from spiral order in FeCl$_3$ to A-type antiferromagnetic order in FeBr$_3$. Using first-principles calculations, we show that a delicate balance between nearest and next-nearest neighbor interactions is responsible for such a transition. These results support the proximity of FeCl$_3$ to a spiral spin liquid state, in which competing interactions and nearly degenerate magnetic $k$-vectors may cause large changes in response to small perturbations.

cond-mat.mtrl-sci↗

arXiv2022

Spin-carrier coupling induced ferromagnetism and giant resistivity peak in EuCd$_2$P$_2$

EuCd$_2$P$_2$ is notable for its unconventional transport: upon cooling the metallic resistivity changes slope and begins to increase, ultimately 100-fold, before returning to its metallic value. Surprisingly, this giant peak occurs at 18K, well above the Néel temperature ($T_N$) of 11.5K. Using a suite of sensitive probes of magnetism, including resonant x-ray scattering and magneto-optical polarimetry, we have discovered that ferromagnetic order onsets above $T_N$ in the temperature range of the resistivity peak. The observation of inverted hysteresis in this regime shows that ferromagnetism is promoted by coupling of localized spins and itinerant carriers. The resulting carrier localization is confirmed by optical conductivity measurements.

cond-mat.str-el↗

arXiv2022

Anisotropy of the magnetic and transport properties in EuZn$_2$As$_2$

Several recent studies have shown that the anisotropy in the magnetic structure of \ECA\ plays a significant role in stabilizing the Weyl nodes. To investigate the relationship between magnetic anisotropy and Weyl physics, we present a comparative study between EuZn$_2$As$_2$ and EuCd$_2$As$_2$ that are isostructural but with different magnetic anisotropy. We performed structural analysis, electronic transport, and magnetization experiments on millimeter-sized single crystals of EuZn$_2$As$_2$, and compared the results to those of EuCd$_2$As$_2$. By combining the first principle calculations and neutron diffraction experiment, we identify the magnetic ground state of EuZn$_2$As$_2$ as A-type antiferromagnetic order with a transition temperature ($T_\mathrm{N}$ = 19.6 K) twice that of EuCd$_2$As$_2$. Like EuCd$_2$As$_2$, the negative magnetoresistance of EuZn$_2$As$_2$ is observed after suppressing the resistivity peak at $T_\mathrm{N}$ with increasing fields. However, the anisotropy in both transport and magnetization are much reduced in EuZn$_2$As$_2$. The difference could be ascribed to the weaker spin-orbit coupling, more localized $d$-orbitals, and a larger contribution from the Eu $s$-orbitals in the zinc compound, as suggested by the electronic band calculations. The same band structure effect could be also responsible for the observation of a smaller non-linear anomalous Hall effect in EuZn$_2$As$_2$ compared to EuCd$_2$As$_2$.

cond-mat.str-el↗

arXiv2021

Large Phonon Thermal Hall Conductivity in a Simple Antiferromagnetic Insulator

Phonons are known to generate a thermal Hall effect in certain insulators, including oxides with rare-earth impurities, quantum paraelectrics, multiferroic materials and cuprate Mott insulators. In each case, a special feature of the material is presumed relevant for the underlying mechanism that confers chirality to phonons in a magnetic field. The question is whether a phonon Hall effect is an unusual occurrence - linked to special characteristics such as skew scattering off rare-earth impurities, structural domains, ferroelectricity, ferromagnetism - or a much more common property of insulators than hitherto believed. To help answer this question, we have turned to a simple insulator, with none of the previously encountered special features: the cubic antiferromagnet Cu$_3$TeO$_6$. We find that it has the largest thermal Hall conductivity $κ_{\rm{xy}}$ of any insulator so far. We show that this record-high $κ_{\rm{xy}}$ signal is due to phonons and it does not require the presence of magnetic order, as it persists above the ordering temperature. We conclude that the phonon Hall effect is likely to be a fairly common property of solids.

cond-mat.str-el↗

arXiv2021

Synthesis, structure and properties of layered phosphide nitrides $Ak$Th$_2$Mn$_4$P$_4$N$_2$ ($Ak$ = Rb, Cs)

We report the design, synthesis, structure, and properties of two complex layered phosphide nitrides, $Ak$Th$_2$Mn$_4$P$_4$N$_2$ ($Ak$ = Rb, Cs), which contain anti-fluorite-type [Mn$_2$P$_2$] bilayers separated by fluorite-type [Th2N2] layers as a result of the intergrowth between AkMn$_2$P$_2$ and ThMnPN. The new compounds are featured with an intrinsic hole doping associated with the interlayer charge transfer and a built-in chemical pressure from the [Th$_2$N$_2$] layers, both of which are reflected by the changes in the lattice and the atomic position of phosphorus. The measurements of magnetic susceptibility, electrical resistivity, and specific heat indicate existence of local moments as well as itinerant electrons in relation with d-p hybridizations. The expected dominant antiferromagnetic interactions with enhanced d-p hybridizations were demonstrated by the first-principles calculations only when additional Coulomb repulsions are included. The density of states at the Fermi level derived from the specific-heat analysis are 3.5 and 7.5 times of the calculated ones for Ak = Rb and Cs, respectively, suggesting strong electron correlations in the title compounds.

cond-mat.mtrl-sci↗

arXiv2021

Antiferromagnetic Order and Spin-Canting Transition in the Corrugated Square Net Compound Cu$_3$(TeO$_4$)(SO$_4$)$\cdot$H$_2$O

Strongly correlated electrons in layered perovskite structures have been the birthplace of high-temperature superconductivity, spin liquid, and quantum criticality. Specifically, the cuprate materials with layered structures made of corner sharing square planar CuO$_4$ units have been intensely studied due to their Mott insulating grounds state which leads to high-temperature superconductivity upon doping. Identifying new compounds with similar lattice and electronic structures has become a challenge in solid state chemistry. Here, we report the hydrothermal crystal growth of a new copper tellurite sulfate Cu$_3$(TeO$_4$)(SO$_4$)$\cdot$H$_2$O, a promising alternative to layered perovskites. The orthorhombic phase (space group $Pnma$) is made of corrugated layers of corner-sharing CuO$_4$ square-planar units that are edge-shared with TeO$_4$ units. The layers are linked by slabs of corner-sharing CuO$_4$ and SO$_4$. Using both the bond valence sum analysis and magnetization data, we find purely Cu$^{2+}$ ions within the layers, but a mixed valence of Cu$^{2+}$/Cu${^+}$ between the layers. Cu$_3$(TeO$_4$)(SO$_4$)$\cdot$H$_2$O undergoes an antiferromagnetic transition at $T_N$=67 K marked by a peak in the magnetic susceptibility. Upon further cooling, a spin-canting transition occurs at $T^{\star}$=12 K evidenced by a kink in the heat capacity. The spin-canting transition is explained based on a $J_1$-$J_2$ model of magnetic interactions, which is consistent with the slightly different in-plane super-exchange paths. We present Cu$_3$(TeO$_4$)(SO$_4$)$\cdot$H$_2$O as a promising platform for the future doping and strain experiments that could tune the Mott insulating ground state into superconducting or spin liquid states.

cond-mat.str-el↗