arXiv subjects

Jinhu Yang

Publications and source records attributed to Jinhu Yang.

At least 19 recordsLinked to original sources

arXiv2026

Large magnetoresistance and weak-antilocalization in the nodal-line semimetal VP2

After growing successfully high quality VP$_2$ single crystals, we studied systematically their longitudinal $ρ_{xx}(T)$ and Hall resistivity $ρ_{yx}(T)$ at various magnetic fields, combining the electronic band and Fermi surface (FS) calculations. Band calculations reveal that VP$_2$ is a type-II nodal-line semimetal, evidenced by the Hall resistivity measurements. It is found that the magnetoresistance (MR) at higher magnetic fields exhibits a linear behavior and does not show any sign of saturation, reaching 170\% at 40 K up to 9 T, which is determined by the intrinsic electronic structure and dominated by the Lorenz force, demonstrated by the resistivity anisotropy measurements and the numerical simulations. We also found that the existence of small amount magnetic impurities (V$^{4+}$, $S=1/2$, 2.24\%) results in Kondo effect emerging in $ρ_{xx}(T)$, the conductivity at lower magnetic fields exhibits a typical weak anti-localization (WAL) behavior. These results illustrate that VP$_2$ is a platform to study the electronic transport properties of a topological material containing magnetic impurities.

cond-mat.str-el↗

arXiv2025

Topological nontrivial berry phase in altermagnet CrSb

The study of topological properties in magnetic materials has long been one of the forefront research areas in condensed matter physics. CrSb, as a prototypical candidate material for altermagnetism, has attracted significant attention due to its unique magnetic properties. This system provides a novel platform for exploring the intrinsic relationship between altermagnetic order and exotic topological states. In this study, we combine systematic electrical transport experiments with first-principles calculations to investigate the possible realization mechanisms of topological semimetal states in CrSb and their manifestations in quantum transport phenomena. Our high field magneto-transport measurements reveal that the magnetoresistance of CrSb exhibits no sign of saturation up to 35 T, following a distinct power-law dependence with an exponent of 1.48. The nonlinear Hall resistivity further indicates a multiband charge transport mechanism. Under high magnetic fields, we observe pronounced Shubnikov-de Haas (SdH) quantum oscillations and discernible Zeeman-effect-induced band splitting at 1.6 K. Systematic Fermi surface and band calculations combined with Berry phase analysis confirm the nontrivial topological character of this material (with a Berry phase approaching π). These findings not only provide crucial experimental evidence for understanding the electronic structure of CrSb, but also establish an important foundation for investigating topological quantum states in altermagnets.

cond-mat.mtrl-sci↗

arXiv2024

Universal Scaling Behavior of Transport Properties in Non-Magnetic RuO$_{2}$

As a prototypical altermagnet, RuO$_{2}$ has been subject to many controversial reports regarding its magnetic ground state and the existence of crystal Hall effects. We obtained high-quality RuO$_{2}$ single crystal with a residual resistivity ratio (RRR = 152), and carefully measured its magnetization, longitudinal resistivity ($ρ_{xx}$) and Hall resistivity ($ρ_{yx}$) up to 35 T magnetic field. We also calculated its electronic band, Fermi surface, and conducted numerical simulations for its transport properties. It was found that no magnetic transition occurs below 400 K, and that all the transport properties are consistent with the numerical simulations results, indicating that the magnetotransport properties originate from the intrinsic electronic structures and are dominated by the Lorentz force. Particularly, no crystal Hall effects were observed in our RuO$_{2}$ samples and both magnetoresistance and Hall resistivity follow scaling behavior. These results demonstrate that RuO$_{2}$ is a typical semimetal, rather than an altermagnet.

cond-mat.mtrl-sci↗

arXiv2024

Scaling Behavior of Magnetoresistance and Hall Resistivity in Altermagnet CrSb

The discovery of altermagnet (AM) marks a significant advancement in magnetic materials, combining characteristics of both ferromagnetism and antiferromagnetism. In this Letter, we focus on CrSb, which has been verified to be an AM and to exhibit substantial spin splitting near the Fermi level. After successfully growing high-quality CrSb single crystals, we performed comprehensive magnetization, magnetoresistance (MR), and Hall resistivity measurements, along with the electronic structure, and Fermi surface (FS) calculations, as well as the magneto-transport property numerical simulations. An antiferromagnetic transition occurring at $T_{N}$ = 712 K was reconfirmed. It was found that both experimental MR and Hall resistivity are consistent with the numerical simulation results, and exhibit obvious scaling behavior. The nonlinear Hall resistivity is due to its multi-band structure, rather than an anomalous Hall effect (AHE). Especially, the scaling behavior in Hall resistivity is first observed within an AM material. These findings demonstrate that the magneto-transport properties in CrSb originate from the intrinsic electronic structure and are dominated by the Lorentz force.

cond-mat.mtrl-sci↗

arXiv2022

Superconductivity in the nodal-line compound La$_3$Pt$_3$Bi$_4$

Owing to the specific topological states in nodal-line semimetals, novel topological superconductivity is expected to emerge in these systems. In this letter, by combination of the first-principles calculations and resistivity, susceptibility and specific heat measurements, we demonstrate that La$_3$Pt$_3$Bi$_4$ is a topologically nontrivial nodal-ring semimetal protected by the gliding-mirror symmetry even in the presence of spin-orbit coupling. Meanwhile, we discover bulk superconductivity with a transition temperature of $\sim$1.1 K, and an upper critical field of $\sim$0.41 T. These findings demonstrate that La$_3$Pt$_3$Bi$_4$ provides a material platform for studying novel superconductivity in the nodal-ring system.

cond-mat.supr-con↗

arXiv2022

Superconductivity in TlBi$_2$ with a large Kadowaki-Woods ratio

In this article, the superconducting and normal state properties of TlBi$_2$ with the AlB$_2$-type structure were studied by the resistivity, magnetization and specific heat measurements. It was found that bulk superconductivity with $T_{C}$ = 6.2 K emerges in TlBi$_2$, which is a phonon-mediated $s$-wave superconductor with a strong electron-phonon coupling ($λ$$_{ep}$ = 1.38) and a large superconducting gap ($Δ_{0}$/$k_{B}T_{C}$ = 2.25). We found that the $ρ$($T$) exhibits an unusual $T$-linear dependence above 50 K, and can be well described by the Fermi-liquid theory below 20 K. Interestingly, its Kadowaki-Woods ratio $A/γ^{2}$ [9.2$\times$10$^{-5}$ $μΩ$ cm(mol K$^{2}$/mJ)$^{2}$] is unexpectedly one order of magnitude larger than that obtained in many heavy Fermi compounds, although the electron correlation is not so strong.

cond-mat.supr-con↗

arXiv2021

Large Magnetoresistance and Nontrivial Berry Phase in Nb3Sb Crystals with A15 Structure

Compounds with the A15 structure have attracted extensive attention due to their superconductivity and nontrivial topological band structure. We have successfully grown Nb$_3$Sb single crystals with a A15 structure and systematically measured the longitudinal resistivity, Hall resistivity and quantum oscillations in magnetization. Similar to other topological trivial/nontrivial semimetals, Nb$_3$Sb, exhibits large magnetoresistance (MR) at low temperatures (717$\%$, 2 K and 9 T), unsaturating quadratic field dependence of MR and up-turn behavior in $ρ_{xx}$(\emph{T}) curves under magnetic field, which is considered to result from a perfect hole-electron compensation, as evidenced by the Hall resistivity measurements. The nonzero Berry phase obtained from the de-Hass van Alphen (dHvA) oscillations demonstrates that Nb$_3$Sb is topologically nontrivial. These results indicate that Nb$_{3}$Sb superconductor is also a semimetal with large MR and nontrivial Berry phase, indicating that Nb$_{3}$Sb may be another platform to search for Majorana zero-energy mode.

cond-mat.supr-con↗

arXiv2021

Extremely large magnetoresistance in the "ordinary" metal ReO3

The extremely large magnetoresistance (XMR) observed in many topologically nontrivial and trivial semimetals has attracted much attention in relation to its underlying physical mechanism. In this paper, by combining the band structure and Fermi surface (FS) calculations with the Hall resistivity and de Haas-Van Alphen (dHvA) oscillation measurements, we studied the anisotropy of magnetoresistance (MR) of ReO$_3$ with a simple cubic structure, an "ordinary" nonmagnetic metal considered previously. We found that ReO$_3$ exhibits almost all the characteristics of XMR semimetals: the nearly quadratic field dependence of MR, a field-induced upturn in resistivity followed by a plateau at low temperatures, high mobilities of charge carriers. It was found that for magnetic field \emph{H} applied along the \emph{c} axis, the MR exhibits an unsaturated \emph{H}$^{1.75}$ dependence, which was argued to arise from the complete carrier compensation supported by the Hall resistivity measurements. For \emph{H} applied along the direction of 15$^\circ$ relative to the \emph{c} axis, an unsaturated \emph{H}$^{1.90}$ dependence of MR up to 9.43~$\times$~$10^3$$\%$ at 10~K and 9~T was observed, which was explained by the existence of electron open orbits extending along the $k_{x}$ direction. Two mechanisms responsible for XMR observed usually in the semimetals occur also in the simple metal ReO$_3$ due to its peculiar FS (two closed electron pockets and one open electron pocket), once again indicating that the details of FS topology are a key factor for the observed XMR in materials.

cond-mat.str-el↗

arXiv2020

Magnetoresistance and Kondo effect in the nodal-line semimetal VAs$_2$

We performed calculations of the electronic band structure and the Fermi surface as well as measured the longitudinal resistivity $ρ_{xx}(T,H)$, Hall resistivity $ρ_{xy}(T,H)$, and magnetic susceptibility as a function of temperature and various magnetic fields for VAs$_2$ with a monoclinic crystal structure. The band structure calculations show that VAs$_2$ is a nodal-line semimetal when spin-orbit coupling is ignored. The emergence of a minimum at around 11 K in $ρ_{xx}(T)$ measured at $H$ = 0 demonstrates that an additional magnetic impurity (V$^{4+}$, $S$ = 1/2) occurs in VAs$_2$ single crystals, evidenced by both the fitting of $ρ_{xx}(T)$ data and the susceptibility measurements. It was found that a large positive magnetoresistance (MR) reaching 649\% at 10 K and 9 T, its nearly quadratic field dependence, and a field-induced up-turn behavior of $ρ_{xx}(T)$ emerge also in VAs$_2$, although MR is not so large due to the existence of additional scattering compared with other topological nontrival/trival semimetals. The observed properties are attributed to a perfect charge-carrier compensation, which is evidenced by both calculations relying on the Fermi surface and the Hall resistivity measurements. These results indicate that the compounds containing V ($3d^3 4s^2$) element as a platform for studying the influence of magnetic impurities to the topological properties.

cond-mat.str-el↗

arXiv2020

Bulk Superconductivity in the Dirac Semimetal TlSb

A feasible strategy to realize the Majorana fermions is searching for a simple compound with both bulk superconductivity and Dirac surface states. In this paper, we performed calculations of electronic band structure, the Fermi surface and surface states, as well as measured the resistivity, magnetization, specific heat for TlSb compound with a CsCl-type structure. The band structure calculations show that TlSb is a Dirac semimetal when spin-orbit coupling is taken into account. Meanwhile, we first found that TlSb is a type-II superconductor with $T_c$ = 4.38 K, $H_{c1}$(0) = 148 Oe, $H_{c2}$(0) = 1.12 T and $κ_{GL}$ = 10.6, and confirmed it to be a moderately coupled s-wave superconductor. Although we can not determine which bands near the Fermi level $E_F$ to be responsible for superconductivity, its coexistence with the topological surface states implies that TlSb compound may be a simple material platform to realize the fault-tolerant quantum computations.

cond-mat.supr-con↗

arXiv2020

Metamagnetic transitions and anomalous magnetoresistance in EuAg$_4$As$_2$ single crystal

In this paper, the magnetic and transport properties were systematically studied for EuAg$_4$As$_2$ single crystals, crystallizing in a centrosymmetric trigonal CaCu$_4$P$_2$ type structure. It was confirmed that two magnetic transitions occur at $\textit{T}$$_{N1}$ = 10 K and $\textit{T}$$_{N2}$ = 15 K, respectively. With the increasing field, the two transitions are noticeably driven to lower temperature. At low temperatures, applying a magnetic field in the $\textit{ab}$ plane induces two successive metamagnetic transitions. For both $\textit{H}$ $\parallel$ $\textit{ab}$ and $\textit{H}$ $\parallel$ $\textit{c}$, EuAg$_4$As$_2$ shows a positive, unexpected large magnetoresistance (up to 202\%) at low fields below 10 K, and a large negative magnetoresistance (up to -78\%) at high fields/intermediate temperatures. Such anomalous field dependence of magnetoresistance may have potential application in the future magnetic sensors. Finally, the magnetic phase diagrams of EuAg$_{4}$As$_{2}$ were constructed for both $\textit{H}$ $\parallel$ $\textit{ab}$ and $\textit{H}$ $\parallel$ $\textit{c}$.

cond-mat.mtrl-sci↗

arXiv2020

Linear and quadratic magnetoresistance in the semimetal SiP2

Multiple mechanisms for extremely large magnetoresistance (XMR) found in many topologically nontrivial/trivial semimetals have been theoretically proposed, but experimentally it is unclear which mechanism is responsible in a particular sample. In this article, by the combination of band structure calculations, numerical simulations of magnetoresistance (MR), Hall resistivity and de Haas-van Alphen (dHvA) oscillation measurements, we studied the MR anisotropy of SiP$_{2}$ which is verified to be a topologically trivial, incomplete compensation semimetal. It was found that as magnetic field, $H$, is applied along the $a$ axis, the MR exhibits an unsaturated nearly linear $H$ dependence, which was argued to arise from incomplete carriers compensation. For the $H$ $\parallel$ [101] orientation, an unsaturated nearly quadratic $H$ dependence of MR up to 5.88 $\times$ 10$^{4}$$\%$ (at 1.8 K, 31.2 T) and field-induced up-turn behavior in resistivity were observed, which was suggested due to the existence of hole open orbits extending along the $k_{x}$ direction. Good agreement of the experimental results with the simulations based on the calculated Fermi surface (FS) indicates that the topology of FS plays an important role in its MR.

cond-mat.mtrl-sci↗

arXiv2020

Large magnetoresistance and non-zero Berry phase in the nodal-line semimetal MoO2

We performed calculations of the electronic band structure and the Fermi surface as well as measured the longitudinal resistivity rhoxx(T,H), Hall resistivity rhoxy(T,H) and quantum oscillations of the magnetization as a function of temperature at various magnetic fields for MoO2 with monoclinic crystal structure. The band structure calculations show that MoO2 is a nodal-line semimetal when spin-orbit coupling is ignored. It was found that a large magnetoresistance reaching 5.03x10^4% at 2 K and 9 T, its nearly quadratic field dependence and a field-induced up-turn behavior of rhoxx(T), the characteristics common for many topologically non-trivial as well as trivial semimetals, emerge also in MoO2. The observed properties are attributed to a perfect charge-carrier compensation, evidenced by both calculations relying on the Fermi surface topology and the Hall resistivity measurements. Both the observation of negative magnetoresistance for magnetic field along the current direction and the non-zero Berry phase in de Haas-van Alphen measurements indicate that pairs of Weyl points appear in MoO2, which may be due to the crystal symmetry breaking. These results highlight MoO2 as a new platform materials for studying the topological properties of oxides.

cond-mat.mtrl-sci↗

arXiv2018

A Single-Crystal Neutron Diffraction Study on Magnetic Structure of CsCo2Se2

The magnetic structure of CsCo2Se2 was investigated using single-crystal neutron diffraction technique. An antiferromagnetic transition with the propagation vector (0,0,1) was observed at T_N = 78 K. The Co magnetic moment 0.772(6) μ_B at 10 K pointing in the basal plane couples ferromagnetically in the plane which stacks antiferromagnetically along the c direction. Tuning and suppressing the interplane antiferromagnetic interaction may be crucial to induce the material to a superconducting state.

cond-mat.str-el↗

arXiv2018

Extremely large magnetoresistance in topologically trivial semimetal $α$-WP$_2$

Extremely large magnetoresistance (XMR) was recently discovered in many non-magnetic materials, while its underlying mechanism remains poorly understood due to the complex electronic structure of these materials. Here, we report an investigation of the $α$-phase WP$_2$, a topologically trivial semimetal with monoclinic crystal structure (C2/m), which contrasts to the recently discovered robust type-II Weyl semimetal phase in $β$-WP$_2$. We found that $α$-WP$_2$ exhibits almost all the characteristics of XMR materials: the near-quadratic field dependence of MR, a field-induced up-turn in resistivity following by a plateau at low temperature, which can be understood by the compensation effect, and high mobility of carriers confirmed by our Hall effect measurements. It was also found that the normalized MRs under different magnetic fields has the same temperature dependence in $α$-WP$_2$, the Kohler scaling law can describe the MR data in a wide temperature range, and there is no obvious change in the anisotropic parameter $γ$ value with temperature. The resistance polar diagram has a peanut shape when field is rotated in $\textit{ac}$ plane, which can be understood by the anisotropy of Fermi surface. These results indicate that both field-induced-gap and temperature-induced Lifshitz transition are not the origin of up-turn in resistivity in the $α$-WP$_2$ semimetal. Our findings establish $α$-WP$_2$ as a new reference material for exploring the XMR phenomena.

cond-mat.str-el↗

arXiv2016

Experimental Determination of the Fermi Surface of Sr3Ir4Sn13

The stannide family of materials A3T4Sn13 (A = La,Sr,Ca, T = Ir,Rh) is interesting due to the interplay between a tunable lattice instability and phonon-mediated superconductivity with Tc ~ 5-7 K. In Sr3Ir4Sn13 a structural transition temperature T* ~ 147 K associated with this instability has been reported, which is believed to result from a superlattice distortion of the high temperature phase on cooling. Here we report the first experimental study of the electronic structure of a member of this material family - Sr3Ir4Sn13 through measurements of quantum oscillations and comparison with density functional theory calculations. Our measurements reveal good agreement with theory using the lattice parameters consistent with a body-centred cubic lattice of symmetry I-43d of the low temperature phase. The study of the fermiology of Sr3Ir4Sn13 we present here should help inform models of multiband superconductivity in the superconducting stannides.

cond-mat.supr-con↗

arXiv2015

Superconductivity in a new layered nickel-selenide CsNi2Se2

The physical properties of CsNi$_{2}$Se$_{2}$ were characterized by electrical resistivity, magnetization and specific heat measurements. We found that the stoichiometric CsNi$_{2}$Se$_{2}$ compound is a superconductor with a transition temperature \textit{T$_{c}$}=2.7K. A large Sommerfeld coefficient $γ$$_{n}$ ($\sim$77.90 mJ/mol$\cdot$K$^{-2}$), was obtained from the normal state electronic specific heat. However, the Kadowaki-Woods ratio of CsNi$_{2}$Se$_{2}$ was estimated to be about 0.041$\times$10$^{-5}$ $μΩ$$\cdot$cm(mol$\cdot$K/mJ)$^{2}$, indicating the absence of strong electron-electron correlations in this compound. In the superconducting state, we found that the zero-field electronic specific heat data, $C_{es}(T)$ (0.5K $\leq$ T $<$ 2.6K), can be well fitted with a two-gap BCS model. The comparison with the results of the density functional theory (DFT) calculations suggested that the large $γ$$_{n}$ in the nickel-selenide superconductors may be related to the large Density of States (DOS) at the fermi surface.

cond-mat.supr-con↗

arXiv2015

Unsaturated both large positive and negative magnetoresistance in Weyl Semimetal TaP

After growing successfully TaP single crystal, we measured its longitudinal resistivity (rhoxx) and Hall resistivity (rhoyx) at magnetic fields up to 9T in the temperature range of 2-300K. It was found that at 2K its magnetoresistivity (MR) reaches to 328000 percent, at 300K to 176 percent at 8T, and both do not appear saturation. We confirmed that TaP is indeed a low carrier concentration, hole-electron compensated semimetal, with a high mobility of hole muh=371000 cm2V-1s-1, and found that a magnetic-field-induced metal-insulator transition occurs at room temperature. Remarkably, as a magnetic field (H) is applied in parallel to the electric field (E), the negative MR due to chiral anomaly is observed, and reaches to -3000 percent at 9T without any signature of saturation, too, which distinguishes with other Weyl semimetals (WSMs). The analysis on the Shubnikov-de Haas (SdH) oscillations superimposing on the MR reveals that a nontrivial Berry phase with strong offset of 0.3958 realizes in TaP, which is the characteristic feature of the charge carriers enclosing a Weyl nodes. These results indicate that TaP is a promising candidate not only for revealing fundamental physics of the WSM state but also for some novel applications.

cond-mat.str-el↗