arXiv subjects

C. -L. Huang

Publications and source records attributed to C. -L. Huang.

At least 19 recordsLinked to original sources

arXiv2026

Multistage spin correlations in the $s$ = 1/2 stuffed hyper-star lattice Li$_{2}$Cu$_{2}$(MoO$_{4}$)$_{3}$

Star lattice, which can be visualized as a honeycomb network with each vertex replaced by a triangle, provides a rare platform for realizing exotic quantum states such as quantum spin liquids and disorder-driven random-singlet (RS) states. Herein, we investigate the ground-state properties of the three-dimensional (3D) stuffed hyper-star lattice Li$_2$Cu$_2$(MoO$_4$)$_3$, which exhibits a crossover from short-range spin correlations to a disorder-driven RS-like state below $T^{*}\sim$15.8 K. Thermodynamic and microscopic measurements capture this crossover through a change in the power-law behavior of various observables, from $\sim T^{0.25}$ for $T > T^{*}$ to $\sim T^{-0.50}$ for $T < T^{*}$. Upon further cooling, a quasi-frozen state emerges near $T_{\rm f} = 0.32$ K, likely associated with weakly coupled spin chains within the hyper-star spin network. Our results underscore the crucial role of orphan spins and weak residual interactions in stabilizing a disorder-driven quantum-disordered state in 3D.

cond-mat.str-el↗

arXiv2025

Possible Bose-Einstein condensation of magnons in a S = 5/2 honeycomb lattice

Quantum magnets offer a unique platform for exploring exotic quantum phases and quantum phase transitions through external magnetic fields. A prominent example is the field-induced Bose--Einstein condensation (BEC) of magnons near the saturation field. While this behavior has been observed in low-spin systems, its realization in high-spin, quasi-two-dimensional magnets -- where multiple on-site excitations are possible -- remains exceptionally rare. Here, we report thermodynamic and density functional theory results on single crystals of the honeycomb-lattice antiferromagnet K$_{4}$MnMo$_{4}$O$_{15}$ with $S = 5/2$. The system undergoes a field-induced transition to a fully polarized state at the critical field $μ_{0}H_{\rm s} = 6.4$~T. Our results reveal possible thermodynamic signatures of magnon BEC, $T_{\mathrm{N}} \sim (H_{\rm s} - H)^{2/d}$ ($d = 3$), expanding the purview of BEC-driven quantum criticality to a high-spin, quasi-two-dimensional antiferromagnets with negligibly small anisotropy.

cond-mat.str-el↗

arXiv2025

Spin dynamics and 1/3 magnetization plateau in a coupled distorted diamond chain compound K2Cu3(MoO4)4

We investigate magnetic properties of the $s$ = 1/2 compound K$_{2}$Cu$_{3}$(MoO$_{4}$)$_{4}$ by combining magnetic susceptibility, magnetization, specific heat, and electron spin resonance (ESR) with density functional calculations. Its monoclinic structure features alternating Cu$^{2+}$ ($s$ = 1/2) monomers and edge-shared dimers linked by MoO$_{4}$ units, forming a distorted diamond chain along the $a$-axis. Antiferromagnetic order occurs at $T_{\rm N}$ = 2.3 K, as evident from a $λ$-type anomaly in specific heat and magnetic susceptibility derivatives. Inverse magnetic susceptibility reveals coexisting ferro- and antiferromagnetic interactions. Specific heat and ESR data show two characteristic temperatures: one at 20 K, associated with spin-singlet formation in Cu$_{2}$O$_{9}$ dimers, and another at 3.68 K, indicating short-range correlations between dimers and monomers. Magnetization measurements reveal a metamagnetic transition at 2.6 T and a critical magnetic field $μ_{0}H_{c}$ = 3.4 T, where a 1/3 magnetization plateau emerges with saturation near 0.35 $μ_{\rm B}$. Low-temperature specific heat and magnetization data reveal the suppression of long-range order at $μ_{0}H_{c}$, enabling the construction of a temperature-magnetic field phase diagram showing multiple magnetic phases near the $μ_{0}H_{c}$. Density functional theory confirms a distorted diamond chain with $J_{1}$ dimers and competing $J_2$, $J_4$, $J_3$, and $J_5$ interactions with monomer spins as an effective low-temperature spin model.

cond-mat.str-el↗

arXiv2024

Magnetic properties of binary alloys Ni1-xMox and Ni1-yCuy close to critical concentrations

The search for the ferromagnetic quantum critical point (FM QCP) has always been a captivating research topic in the scientific community. In pursuit of this goal, we introduced nonmagnetic transition metals to alloy with elemental nickel, and studied the magnetic properties of nickel binary alloys Ni1-xMox and Ni1-yCuy as a function of x and y up to the critical concentrations x_{cr} and y_{cr} at which the FM transition T_C disappears. T_C-x(y) phase diagrams were constructed via the Arrott-Noakes scaling of magnetization data. An enhanced Sommerfeld coefficient (the value of C/T as T \rightarrow 0) is observed near y_{cr}, manifesting the effect of quantum fluctuations near the quantum phase transition. It is evident that C/T diverges with -logT down to 0.1 K in the vicinity of y_{cr}, suggests the plausible FM QCP in Ni1-yCuy. However, in the case of Ni1-xMox, although the enhancement of the Sommerfeld coefficient is also observed near x_{cr}, the spin glass behavior is identified through the ac magnetic susceptibility measurement. This observation rules out the possibility of the existence of the FM QCP in Ni1-xMox.

cond-mat.str-el↗

arXiv2024

Physical properties and electronic structure of the two-gap superconductor V$_{2}$Ga$_{5}$

We present a thorough investigation of the physical properties and superconductivity of the binary intermetallic V2Ga5. Electrical resistivity and specific heat measurements show that V2Ga5 enters its superconducting state below Tsc = 3.5 K, with a critical field of Hc2,perp c(Hc2,para c) = 6.5(4.1) kOe. With H perp c, the peak effect was observed in resistivity measurements, indicating the ultrahigh quality of the single crystal studied. The resistivity measurements under high pressure reveal that the Tsc is suppressed linearly with pressure and reaches absolute zero around 20 GPa. Specific heat and muon spin relaxation measurements both indicate that the two-gap s-wave model best describes the superconductivity of V2Ga5. The spectra obtained from angle-resolved photoemission spectroscopy measurements suggest that two superconducting gaps open at the Fermi surface around the Z and Γ points. These results are verified by first-principles band structure calculations. We therefore conclude that V2Ga5 is a phonon-mediated two-gap s-wave superconductor

cond-mat.supr-con↗

arXiv2024

Non-Fermi-liquid behavior in a ferromagnetic heavy fermion system CeTi$_{1-x}$V$_{x}$Ge$_{3}$

An investigation of the thermodynamic and electrical transport properties of the isoelectronic chemical substitution series CeTi$_{1-x}$V$_{x}$Ge$_{3}$ (CTVG) single crystals is reported. As x increases, the ferromagnetic (FM) transition temperature is suppressed, reaching absolute zero at the critical concentration x = 0.4, where a non-Fermi-liquid low-temperature specific heat and electrical resistivity, as well as the hyperscaling of specific heat and magnetization are found. Our study clearly identifies an FM quantum critical point (QCP) in CTVG. The obtained critical exponents suggest that CTVG falls in the preasymptotic region of the disorder-tuned FM QCP predicted by the Belitz-Kirkpatrick-Vojta theory.

cond-mat.str-el↗

arXiv2022

Field-induced quantum critical point in the new itinerant antiferromagnet Ti$_3$Cu$_4$

New phases of matter emerge at the edge of magnetic instabilities. In local moment systems, such as heavy fermions, the magnetism can be destabilized by pressure, chemical doping, and, rarely, by magnetic field, towards a zero-temperature transition at a quantum critical point (QCP). Even more rare are instances of QCPs induced by pressure or doping in itinerant moment systems, with no known examples of analogous field-induced \textit{T} = 0 transitions. Here we report the discovery of a new itinerant antiferromagnet with no magnetic constituents, in single crystals of Ti$_3$Cu$_4$ with $T_N$ = 11.3 K. Band structure calculations point to an orbital-selective, spin density wave ground state, a consequence of the square net structural motif in Ti$_3$Cu$_4$. A small magnetic field, $H_C$ = 4.87 T, suppresses the long-range order via a continuous second-order transition, resulting in a field-induced QCP. The magnetic Grüneisen ratio diverges as $H \rightarrow H_C$ and $T\rightarrow0$, with a sign change at $H_C$ and $T^{-1}$ scaling at $H~=~H_C$, providing evidence from thermodynamic measurements for quantum criticality for $H \parallel c$. Non-Fermi liquid (NFL) to Fermi liquid (FL) crossover is observed close to the QCP, as revealed by the power law behavior of the electrical resistivity.

cond-mat.str-el↗

arXiv2020

Quantum critical point in the itinerant ferromagnet Ni$_{1-x}$Rh$_x$

We report a chemical substitution-induced ferromagnetic quantum critical point in polycrystalline Ni$_{1-x}$Rh$_x$ alloys. Through magnetization and muon spin relaxation measurements, we show that the ferromagnetic ordering temperature is suppressed continuously to zero at $x_{crit} = 0.375$ while the magnetic volume fraction remains 100% up to $x_{crit}$, pointing to a second order transition. Non-Fermi liquid behavior is observed close to $x_{crit}$, where the electronic specific heat $C_{el}/T$ diverges logarithmically, while immediately above $x_{crit}$ the volume thermal expansion coefficient $α_{V}/T$ and the Grüneisen ratio $Γ= α_{V}/C_{el}$ both diverge logarithmically in the low temperature limit, further indication of a ferromagnetic quantum critical point in Ni$_{1-x}$Rh$_x$.

cond-mat.str-el↗

arXiv2019

Effect of synthesis conditions on the electrical resistivity of TiSe$_2$

Dilute impurities and growth conditions can drastically affect the transport properties of TiSe$_2$, especially below the charge density wave transition. In this paper, we discuss the effects of cooling rate, annealing time and annealing temperature on the transport properties of TiSe$_2$: slow cooling of polycrystalline TiSe$_2$ post-synthesis drastically increases the low temperature resistivity, which is in contrast to the metallic behavior of single-crystalline TiSe$_2$ due to charge doping from the residual iodine transport agent. A logarithmic increase of resistivity upon cooling and negative magnetoresistance with a sharp cusp around zero field are observed for the first time for the polycrystalline TiSe$_2$ samples, pointing to weak-localization effects due to low dimensionality. Annealing at low temperatures has a similar, but less drastic effect. Furthermore, rapid quenching of the polycrystalline samples from high temperatures freezes in disorder, leading to a decrease in the low temperature resistivity.

cond-mat.str-el↗

arXiv2019

Kondo exhaustion and conductive surface states in antiferromagnetic YbIr$_3$Si$_7$

The interplay of Kondo screening and magnetic ordering in strongly correlated materials containing local moments is a subtle problem.[1] Usually the number of conduction electrons matches or exceeds the number of moments, and a Kondo-screened heavy Fermi liquid develops at low temperatures.[2] Changing the pressure, magnetic field, or chemical doping can displace this heavy Fermi liquid in favor of a magnetically ordered state.[3,4] Here we report the discovery of a version of such a `Kondo lattice' material, YbIr$_3$Si$_7$, in which the number of free charge carriers is much less than the number of local moments. This leads to `Kondo exhaustion':[5] the electrical conductivity tends to zero at low temperatures as all the free carriers are consumed in the formation of Kondo singlets. This effect coexists with antiferromagnetic long-range order, with a Néel temperature $T\rm_N = 4.1\,{\rm K}$. Furthermore, the material shows conductive surface states with potential topological nature, and thus presents an exciting topic for future investigations.

cond-mat.str-el↗

arXiv2019

Magnetic excitation emergence relevant to carrier scattering in semimetal Yb$_3$Ir$_4$Ge$_{13}$

Inelastic neutron scattering experiments have been conducted to investigate the semimetal system Yb$_3$Ir$_4$Ge$_{13}$. No clear crystal-field-split levels were observed up to an excitation energy of 60 meV, while a magnetic excitation appears at low energy below approximately 3 meV. This excitation shows a short spatial correlation, and an energy spectrum is reproduced by an imaginary part of generalized magnetic susceptibility on the basis of a damped harmonic oscillator model. The magnetic excitation emerges simultaneously with an anomalous electrical-resistivity enhancement below 20 K. The close relationship between the magnetic and transport behaviors evidences that the semimetal carriers are scattered by magnetic fluctuation dominated by the Yb $4f$ state.

cond-mat.str-el↗

arXiv2019

Ferromagnetic ordering along the hard axis in the Kondo lattice YbIr3Ge7

Ferromagnetic Kondo lattice compounds are far less common than their antiferromagnetic analogs. In this work, we report the discovery of a new ferromagnetic Kondo lattice compound, YbIr3Ge7. Like almost all ferromagnetic Kondo lattice systems, YbIr3Ge7 shows magnetic order with moments aligned orthogonal to the crystal electric field (CEF) easy axis. YbIr3Ge7 is unique in that it is the only member of this class of compounds that crystallizes in a rhombohedral structure with a trigonal point symmetry of the magnetic site, and it lacks broken inversion symmetry at the local moment site. AC magnetic susceptibility, magnetization, and specific heat measurements show that YbIr3Ge7 has a Kondo temperature TK = 14 K and a Curie temperature TC = 2.4 K. Ferromagnetic order occurs along the crystallographic [100] hard CEF axis despite the large CEF anisotropy of the ground state Kramers doublet with a saturation moment along [001] almost four times larger than the one along [100]. This implies that a mechanism which considers the anisotropy in the exchange interaction to explain the hard axis ordering is unlikely. On the other hand, the broad second-order phase transition at TC favors a fluctuation-induced mechanism.

cond-mat.str-el↗

arXiv2018

Magnetotransport in Fe-intercalated \textit{T}S$_2$: the comparison between \textit{T} = Ti and Ta

Sharp magnetization switching and large magnetoresistance were previously discovered in single crystals of 2H-Fe$_x$TaS$_2$ and attributed to the Fe superstructure and its defects. We report similar sharp switching in 1T-Fe$_x$TiS$_2$ ($0.086\;{\leq}\;x\;{\leq}0.703$) and the discovery of large magnetoresistance. The switching field $H_s$ and magnetoresistance are similar to 2H-Fe$_x$TaS$_2$, with a larger than expected bowtie magnetoresistance and a sharp hysteresis loop. Despite previous reports, electron diffraction shows only the $\sqrt{3}{\times}\sqrt{3}$ superstructure in 1T-Fe$_x$TiS$_2$. The Curie and Weiss temperatures remain roughly constant below $x~\sim~1/3$ before monotonically increasing for higher x. By contrast, the switching field and magnetoresistance reach a maximum where defects in the superstructure exist, approach a minimum near perfect superstructures, and remain constant above $x~\sim~ 0.4$. Additionally, an increase in $H_s$ with annealing time is reported. Glassy behavior is shown to coexist within the ferromagnetic state in 1T-Fe$_x$TiS$_2$ for compositions between $0.1$ and $0.703$. A simple model captures the essential phenomenology and explains most similarities and differences between 1T-Fe$_x$TiS$_2$ and 2H-Fe$_x$TaS$_2$, and provides insights into other magnetically intercalated transition metal dichalcogenides.

cond-mat.str-el↗

arXiv2018

Low-carrier density and fragile magnetism in a Kondo lattice system

Kondo-based semimetals and semiconductors are of extensive current interest as a viable platform for strongly correlated states. It is thus important to understand the routes towards such dilute-carrier correlated states. One established pathway is through Kondo effect in metallic non-magnetic analogues. Here we advance a new mechanism, through which Kondo-based semimetals develop out of conduction electrons with a low carrier-density in the presence of an even number of rare-earth sites. We demonstrate this effect by studying the Kondo material Yb3Ir4Ge13 along with its closed-f-shell counterpart, Lu3Ir4Ge13. Through magnetotransport, optical conductivity and thermodynamic measurements, we establish that the correlated semimetallic state of Yb3Ir4Ge13 below its Kondo temperature originates from the Kondo effect of a low carrier conduction-electron background. In addition, it displays fragile magnetism at very low temperatures, which, in turn, can be tuned to a non Fermi liquid regime through Lu-for-Yb substitution. These findings are connected with recent theoretical studies in simplified models. Our results open an entirely new venue to explore the strong correlation physics in a semimetallic environment.

cond-mat.str-el↗

arXiv2018

Effects of chemical disorder in the itinerant antiferromagnet Ti$_{1-x}$V$_x$Au

The fragile nature of itinerant magnetism can be exploited using non-thermal parameters to study quantum criticality. The recently discovered quantum critical point (QCP) in the Sc-doped (hole-like doping) itinerant antiferromagnet TiAu (Ti$_{1-x}$Sc$_{x}$Au) raised questions about the effects of the crystal and electronic structures on the overall magnetic behavior. In this study, doping with V (electron-like doping) in Ti$_{1-x}$V$_{x}$Au introduces chemical disorder which suppresses antiferromagnetic order from $T_{\rm N} =$ 36~K for $x = 0$ down to 10 K for $x =$ 0.15, whereupon a solubility limit is reached. Signatures of non-Fermi-liquid behavior are observed in transport and specific heat measurements similar to Ti$_{1-x}$Sc$_{x}$Au, even though Ti$_{1-x}$V$_{x}$Au is far from a QCP for the accessible compositions $x \leq 0.15$.

cond-mat.str-el↗

arXiv2018

Anomalous metamagnetism in the low carrier density Kondo lattice YbRh3Si7

We report complex metamagnetic transitions in single crystals of the new low carrier Kondo antiferromagnet YbRh3Si7. Electrical transport, magnetization, and specific heat measurements reveal antiferromagnetic order at T_N = 7.5 K. Neutron diffraction measurements show that the magnetic ground state of YbRh3Si7 is a collinear antiferromagnet where the moments are aligned in the ab plane. With such an ordered state, no metamagnetic transitions are expected when a magnetic field is applied along the c axis. It is therefore surprising that high field magnetization, torque, and resistivity measurements with H||c reveal two metamagnetic transitions at mu_0H_1 = 6.7 T and mu_0H_2 = 21 T. When the field is tilted away from the c axis, towards the ab plane, both metamagnetic transitions are shifted to higher fields. The first metamagnetic transition leads to an abrupt increase in the electrical resistivity, while the second transition is accompanied by a dramatic reduction in the electrical resistivity. Thus, the magnetic and electronic degrees of freedom in YbRh3Si7 are strongly coupled. We discuss the origin of the anomalous metamagnetism and conclude that it is related to competition between crystal electric field anisotropy and anisotropic exchange interactions.

cond-mat.str-el↗

arXiv2018

CeIr$_{3}$Ge$_{7}$: a local moment antiferromagnetic metal with extremely low ordering temperature

CeIr$_3$Ge$_7$ is an antiferromagnetic metal with a remarkably low ordering temperature $T_{\rm N}$ = 0.63 K, while most Ce-based magnets order between 2 and 15 K. Thermodynamic and transport properties as a function of magnetic field or pressure do not show signatures of Kondo correlations, interaction competition, or frustration, as had been observed in a few antiferromagnets with comparably low or lower $T_{\rm N}$. The averaged Weiss temperature measured below 10 K is comparable to $T_{\rm N}$ suggesting that the RKKY exchange coupling is very weak in this material. The unusually low $T_{\rm N}$ in CeIr$_3$Ge$_7$ can therefore be attributed to the large Ce-Ce bond length of about 5.7 Å, which is about 1.5 Å larger than in the most Ce-based intermetallic systems.

cond-mat.str-el↗

arXiv2018

Charge density wave behavior and order-disorder in the antiferromagnetic metallic series Eu(Ga_1-xAl_x)_4

The solid solution Eu(Ga_1-xAl_x)_4 was grown in single crystal form to reveal a rich variety of crystallographic, magnetic, and electronic properties that differ from the isostructural end compounds EuGa_4 and EuAl_4, despite the similar covalent radii and electronic configurations of Ga and Al. Here we report the onset of magnetic spin reorientation and metamagnetic transitions for x = 0 - 1 evidenced by magnetization and temperature-dependent specific heat measurements. T_N changes non-monotonously with x, and it reaches a maximum around 20 K for x = 0.50, where the a lattice parameter also shows an extreme (minimum) value. Anomalies in the temperature-dependent resistivity consistent with charge density wave behavior exist for x = 0.50 and 1 only. Density functional theory calculations show increased polarization between the Ga-Al covalent bonds in the x = 0.50 structure compared to the end compounds, such that crystallographic order and chemical pressure are proposed as the causes of the charge density wave behavior.

cond-mat.str-el↗