arXiv subjects

Laura T. Corredor

Publications and source records attributed to Laura T. Corredor.

8 recordsLinked to original sources

arXiv2026

Probing bulk superconductivity in centrosymmetric Te-doped PtBi$_2$ single crystals

The Weyl semimetal $γ$-PtBi$_2$ has been shown to be one of the most promising novel materials, recently proposed as a topological i-wave superconductor. A crucial requirement for observing this physics is the absence of inversion symmetry in its trigonal $P31m$ crystal structure. Centrosymmetry has been reported to be readily restored in the $P\overline{3}m1$ structure upon electron doping, partially substituting Bi with as little as 2% Te. In this work, we synthesized Te-doped PtBi$_{2-x}$Te$_{x}$ samples and thoroughly investigated the bulk superconductivity of selected single crystals with nominal composition PtBi$_{1.96}$Te$_{0.04}$, exhibiting the highest superconducting volume fraction of $\sim100$%. Single crystal XRD measurements confirm the centrosymmetric $P\overline{3}m1$ structure in our samples, whereas bulk superconductivity with a critical temperature of $T_\mathrm{c} \approx 2.4\,$K was observed in magnetization and specific heat measurements. The upper critical fields for two different orientations were determined as $H^{\parallel}_{\mathrm{c2}}(0)\approx 6.3\,$kOe for in-plane and $H^{\perp}_{\mathrm{c2}}(0)\approx 4.7\,$kOe for out-of-plane magnetic fields. Robust superconductivity was also found in resistance and point contact measurements, where the latter showed a slight enhancement of the critical temperature up to $T_\mathrm{c} \sim 3\,$K. Finally, ARPES measurements corroborate the centrosymmetric structure of our samples, showing a single surface termination and the absence of Fermi arcs.

cond-mat.supr-con↗

arXiv2026

Disorder-resilient transition of Helical to Conical ground states in M$_{1/3}$NbS$_2$, M=Cr,Mn

The discovery of chiral helical magnetism (CHM) in Cr$_{1/3}$NbS$_2$ and the stabilization of a chiral soliton lattice (CSL) has attracted considerable interest in view of their potential technological applications. However, there is an ongoing debate regarding whether the sister compound, Mn$_{1/3}$NbS$_2$, which shares the same crystal structure, exhibits similar nontrivial properties which rely on the stabilization of the lack of inversion symmetry at the magnetic ion. In this study, we conduct a comprehensive investigation of the magnetically ordered states of both compounds, using $^{53}$Cr, $^{55}$Mn and $^{93}$Nb nuclear magnetic resonance. Our results, supported by density functional calculations, detect in a high-quality single crystal of Cr$_{1/3}$NbS$_2$ all the signatures of the monoaxial CHM in a magnetic field, identifying it as a textbook NMR case. The detailed understanding of this prototypic behavior provides a reference for Mn$_{1/3}$NbS$_2$. Despite the much larger density of specific defects in this second single crystal, we confirm the presence of a CHM phase in the Mn compound, characterized by a very large critical field for the forced ferromagnetic phase ($\approx 5$ T for H$\parallel\hat c$).

cond-mat.mtrl-sci↗

arXiv2026

Magnetic-field tuning of the spin dynamics in the quasi-2D van der Waals antiferromagnet CuCrP$_{2}$S$_{6}$

The use of antiferromagnets in magnetoelectronic devices as counterparts of ferromagnets is a new, rapidly developing trend in spintronics that leverages antiferromagnetic (AFM) magnons for transmitting of spin currents. Van der Waals (vdW) antiferromagnets are particularly attractive in this respect as they possess tunable magnetic properties and can be easily integrated into spintronic devices. In this work we use electron spin resonance (ESR) spectroscopy to assess the potential of the vdW AFM compound CuCrP$_{2}$S$_{6}$ for magnonic applications by exploring the magnetic field ($H$) dependence of the spectrum of magnon excitations below its AFM ordering temperature $T_{\rm N} \approx 30$ K and the correlated spin dynamics above $T_{\rm N}$. ESR reveals prominent ferromagnetic (FM) spin correlations that persist far above $T_{\rm N}$ suggesting an intrinsically two-dimensional character of the spin dynamics in CuCrP$_{2}$S$_{6}$. Most interestingly, at $T < T_{\rm N}$, CuCrP$_{2}$S$_{6}$ features two non-degenerate, i.e., distinct in energy AFM magnon modes at $H = 0$ which can be tuned to the FM type of collective spin excitations with increasing $H$. These remarkable properties are favorable for the induction and control of unidirectional spin current in CuCrP$_{2}$S$_{6}$ and suggest it as a new functional material for magnetoelectronics.

cond-mat.str-el↗

arXiv2025

Field-induced magnetic phases in the Kitaev candidate Na$_3$Co$_2$SbO$_6$

We report a rich anisotropic magnetic phase diagram of Na$_3$Co$_2$SbO$_6$, a previously proposed cobaltate Kitaev candidate, based on field- and temperature-dependent magnetization, specific heat, and magnetocaloric effect studies. At low temperatures, our experiments uncover a low-lying $j_{\textrm{eff}} = \frac{1}{2}$ state with an antiferromagnetic ground state and pronounced in-plane versus out-of-plane anisotropy. The experimentally identified magnetic phases are theoretically characterized through classical Monte Carlo simulations within an extended Kitaev-Heisenberg model with additional ring exchange interactions. The resulting phase diagram reveals a variety of exotic field-induced magnetic phases, including double-$\textbf{q}$, $\frac{1}{3}$-AFM, zigzag, and vortex phases.

cond-mat.str-el↗

arXiv2025

Strongly Entangled Kondo and Kagome Lattices and the Emergent Magnetic Ground State in Heavy-Fermion Kagome Metal YbV$_6$Sn$_6$

Applying angle-resolved photoemission spectroscopy and density functional theory calculations, we present compelling spectroscopic evidence demonstrating the intertwining and mutual interaction between the Kondo and kagome sublattices in heavy-fermion intermetallic compound YbV$_6$Sn$_6$. We reveal the Yb 4$f$-derived states near the Fermi level, along with the presence of bulk kagome bands and topological surface states. We unveil strong interactions between the 4$f$ and itinerant electrons, where the kagome bands hosting the Dirac fermions and van Hove singularities predominate. Such findings are well described using a $c$-$f$ hybridization model. On the other hand, our systematic characterization of magnetic properties demonstrates an unusually enhanced antiferromagnetic ordering, where the kagome-derived van Hove singularities near $E_F$ play a vital role in determining the unconventional nature of the Ruderman-Kittel-Kasuya-Yosida interaction and Kondo coupling. These unique kagome-state-mediated exchange interactions have never been reported before and could lead to a novel phase diagram and various quantum critical behaviors in YbV$_6$Sn$_6$ and its siblings. Our results not only expand the family of exotic quantum phases entangled with kagome structure to the strongly correlated regime, but also establish YbV$_6$Sn$_6$ as an unprecedented platform to explore unconventional many-body physics beyond the standard Kondo picture.

cond-mat.str-el↗

arXiv2023

Anomalous Hall effect and magnetoresistance in micro-ribbons of the magnetic Weyl semimetal candidate PrRhC2

PrRhC2 belongs to the rare-earth carbides family whose properties are of special interest among topological semimetals due to the simultaneous breaking of both inversion and time-reversal symmetry. The concomitant absence of both symmetries grants the possibility to tune the Weyl nodes chirality and to enhance topological effects like the chiral anomaly. In this work, we report on the synthesis and compare the magnetotransport measurements of a poly- and single crystalline PrRhC2 sample. Using a remarkable and sophisticated technique, the PrRhC2 single crystal is prepared via focused ion beam cutting from the polycrystalline material. Our magnetometric and specific heat analyses reveal a non-collinear antiferromagnetic state below 20K, as well as short-range magnetic correlations and/or magnetic fluctuations well above the onset of the magnetic transition. The transport measurements on the PrRhC2 single crystal display an electrical resistivity peak at 3K and an anomalous Hall effect below 6K indicative of a net magnetization component in the ordered state. Furthermore, we study the angular variation of magnetoresistivities as a function of the angle between the in-plane magnetic field and the injected electrical current. We find that both the transverse and the longitudinal resistivities exhibit fourfold angular dependencies due to higher-order terms in the resistivity tensor, consistent with the orthorhombic crystal symmetry of PrRhC2. Our experimental results may be interpreted as features of topological Weyl semimetallic behavior in the magnetotransport properties.

cond-mat.mtrl-sci↗

arXiv2023

Intermixing-driven surface and bulk ferromagnetism in the quantum anomalous Hall candidate MnBi$_6$Te$_{10}$

The recent realizations of the quantum anomalous Hall effect (QAHE) in MnBi$_2$Te$_4$ and MnBi$_4$Te$_7$ benchmark the (MnBi$_2$Te$_4$)(Bi$_2$Te$_3$)$_n$ family as a promising hotbed for further QAHE improvements. The family owes its potential to its ferromagnetically (FM) ordered MnBi$_2$Te$_4$ septuple layers (SL). However, the QAHE realization is complicated in MnBi$_2$Te$_4$ and MnBi$_4$Te$_7$ due to the substantial antiferromagnetic (AFM) coupling between the SL. An FM state, advantageous for the QAHE, can be stabilized by interlacing the SL with an increasing number $n$ of Bi$_2$Te$_3$ layers. However, the mechanisms driving the FM state and the number of necessary QLs are not understood, and the surface magnetism remains obscure. Here, we demonstrate robust FM properties in MnBi$_6$Te$_{10}$ ($n = 2$) with $T_C \approx 12$ K and establish their origin in the Mn/Bi intermixing phenomenon by a combined experimental and theoretical study. Our measurements reveal a magnetically intact surface with a large magnetic moment, and with FM properties similar to the bulk. Our investigation thus consolidates the MnBi$_6$Te$_{10}$ system as perspective for the QAHE at elevated temperatures.

cond-mat.mtrl-sci↗

arXiv2022

Crystal Growth, Exfoliation and Magnetic Properties of Quaternary Quasi-Two-Dimensional CuCrP$_2$S$_6$

We report optimized crystal growth conditions for the quaternary compound CuCrP$_2$S$_6$ by chemical vapor transport. Compositional and structural characterization of the obtained crystals were carried out by means of energy-dispersive X-ray spectroscopy and powder X-ray diffraction. CuCrP$_2$S$_6$ is structurally closely related to the $M_2$P$_2$S$_6$ family ($M$: transition metal), which contains several compounds that are under investigation as 2D magnets. As-grown crystals exhibit a plate-like, layered morphology as well as a hexagonal habitus. We present successful exfoliation of such as-grown crystals down to thicknesses of 2.8 nm corresponding to 4 layers. CuCrP$_2$S$_6$ crystallizes in the monoclinic space group $C2/c$. Magnetization measurements reveal an antiferromagnetic ground state with $T_\textrm{N} \approx 30$ K and a positive Curie-Weiss temperature in agreement with dominant ferromagnetic intralayer coupling. Specific heat measurements confirm this magnetic phase transition and the magnetic order is suppressed in an external magnetic field of about 6 T (8 T) applied parallel (perpendicular) to the $ab$ plane. At higher temperatures between 140-200 K additional broad anomalies associated with structural changes accompanying antiferroelectric ordering are detected in our specific heat studies.

cond-mat.str-el↗