arXiv subjects

Souvik Chatterjee

Publications and source records attributed to Souvik Chatterjee.

7 recordsLinked to original sources

arXiv2026

Semi-Dirac States and Quantum Linear Magnetoresistance in Helimagnetic Pnictide MnP

Large linear positive magnetoresistance (LPMR) in topological and magnetic materials remains a subject of intense debate, particularly in noncollinear spin systems where spin-dependent scattering complicates charge transport. Manganese phosphide (MnP), a helimagnetic binary pnictide with multiple field-induced magnetic transitions, provides a useful platform to investigate the interplay between complex magnetism and electronic topology. Here, we present a comprehensive experimental and theoretical investigation of phase-dependent magnetotransport in high-quality MnP single crystals. Hall measurements reveal an anomalous Hall effect dominated by skew scattering at high temperatures and a finite topological Hall effect in the noncollinear fan (FAN) and low-temperature screw (SCR) phases. At low temperatures, we observe a large, non-saturating LPMR reaching nearly 800 percent at 4 K and 15 T, with a pronounced linear field dependence in the field-polarized ferromagnetic (FM2) state. First-principles calculations reveal a strongly anisotropic semi-Dirac-like band at the Y point that progressively approaches the Fermi level from the SCR to FAN and FM2 states. Our analysis indicates that the resulting small Fermi pocket can access the extreme quantum-limit regime at experimentally accessible fields, providing a microscopic framework for the observed LPMR within Abrikosov's quantum magnetoresistance theory.

cond-mat.str-el↗

arXiv2025

Deterministic distribution of W-class states in quantum networks

Multipartite entangled states possess a number of non-intuitive properties, making them a useful resource for various quantum information-processing tasks. The three-qubit W-state is one such example where every state is robust to single-qubit loss. However, this state is not suitable for deterministic distribution, and deterministic communication protocols. Here, we focus on the distribution of a non-symmetric version of such states, namely $W_{\mathrm{mod}}$ states. These states belong to the W-class, and have one ebit of entanglement across a specific bipartition, enabling deterministic teleportation and superdense coding. In particular, we describe a few protocols through which these multipartite entangled states can be distributed {\it deterministically} in a quantum network by first preparing them locally in a central node and then transmitting individual qubits to the end nodes. We analyse the performance of these protocols based on the fidelity of the final distributed state, considering all types of noises that can act during the distribution. Finally, we compare the performance of the protocols to the case where the distribution is performed without any central node.

quant-ph↗

arXiv2025

Magnetic Metastability driven Anomalous Hall Effect in Fe$_{x}$TaS$_2$

We report here the observation of robust thermoremanent magnetization (TRM) in Fe-intercalated TaS$_2$ single crystal Fe$_{x}$TaS$_2$, which develops upon cooling under a moderate magnetic field of 500 Oe or higher. The thermoremanence is found to exist in a zero magnetic field up to a temperature as high as 160 K, which is well above the ferromagnetic Curie point ($T_C =$ 90 K) of the sample. The TRM in this compound can be traced back to the strong Ising character and the quasi-two-dimensional nature of the spins. The analysis of the magnetization data indicates the presence of short-range magnetic correlation in the form of a Griffiths singularity above $T_C$ to a temperature as high as 2$T_C$. The TRM is further manifested in the form of a large anomalous Hall effect (AHE) in zero magnetic field. In contrast to TRM, which exists well above $T_C$, the thermoremanent Hall effect vanishes as soon as the sample is heated above $T_C$. This may be an indication that a long-range ordered phase is essential for the emergence of AHE.

cond-mat.str-el↗

arXiv2024

Magnetic field induced arrested state and observation of spontaneous anomalous Hall effect in TbMn$_6$Sn$_6$

The quasi two-dimensional kagome ferrimagnet TbMn$_6$Sn$_6$ is investigated for thermo-remanent magnetization and Hall effects. On cooling under a moderate magnetic field, the sample attains a magnetization value close to the saturation magnetization. Upon heating in a very small magnetic field, the sample continues to maintain the large value of magnetization, which eventually diminishes distinctly at around 200 K manifesting an ultrasharp jump. A similar feature is also observed in the Hall resistivity, which holds its saturation value when heated back in zero field after being field-cooled. The ultrasharp jump in magnetization is also get reflected in our Hall data. The observed data is exotic and can be rooted to the large anisotropy and the strong exchange interaction.

cond-mat.mtrl-sci↗

arXiv2024

Does carrier localization affect the anomalous Hall effect?

The effect of carrier localization due to electron-electron interaction in anomalous Hall effect is elusive and there are contradictory results in the literature. To address the issue, we report here the detailed transport study including the Hall measurements on $\beta$-Mn type cubic compound Co$_7$Zn$_7$Mn$_6$ with chiral crystal structure, which lacks global mirror symmetry. The alloy orders magnetically below $T_c$ = 204 K, and reported to show spin glass state at low temperature. The longitudinal resistivity ($\rho_{xx}$) shows a pronounced upturn below $T_{min}$ = 75 K, which is found to be associated with carrier localization due to quantum interference effect. The upturn in $\rho_{xx}$ shows a $T^{1/2}$ dependence and it is practically insensitive to the externally applied magnetic field, which indicate that electron-electron interaction is primarily responsible for the low-$T$ upturn. The studied sample shows considerable value of anomalous Hall effect below $T_c$. We found that the localization effect is present in the ordinary Hall coefficient ($R_0$), but we failed to observe any signature of localization in the anomalous Hall resistivity or conductivity. The absence of localization effect in the anomalous Hall effect in Co$_7$Zn$_7$Mn$_6$ may be due to large carrier density, and it warrants further theoretical investigations, particularly with systems having broken mirror symmetry.

cond-mat.str-el↗

arXiv2023

Effect of polarisation on two-photon resonance in a large Zeeman manifold

In this study, we present numerical investigations on a large Zeeman manifold in an electromagnetically induced transparency (EIT) medium, focusing on the D1 and D2 lines of 87 Rb as our model system. We examine two distinct models comprising 13 and 16 energy levels, respectively, using pump-probe spectroscopy with varying polarization of the light fields. A longitudinal magnetic field is used, and the ellipticity of both light fields is varied with the constraint that both lights have orthogonal polarization. We discover that in the presence of a longitudinal magnetic field, the change in ellipticity of light polarization induces optical anisotropy. This anisotropy results from the uneven distribution of population among the ground Zeeman levels, leading to the absorption of weak probe light. For a large number of states interacting with different field components, the existence of a steady state depends upon the multi-photon resonance and phase matching conditions. A comment is made on why such conditions are not required in our model, and the assumptions and limitations of the model are also discussed. To validate our numerical findings, we perform experimental measurements at two different magnetic field strengths in the D2 line of 87 Rb. The experimental results align well with our numerical simulations. Specifically, we conclude that the probe transmission spectra at lower magnetic field values (up to 20 G) exhibit similarity for both the D1 and D2 lines of 87 Rb, effectively described by the 13-level model. However, at higher magnetic field values, a more complicated 16-level (or higher) system is necessary to accurately capture the response of the probe in D2 line.

physics.optics↗

arXiv2022

Two-band conduction as a pathway to non-linear Hall effect and unsaturated negative magnetoresistance in the martensitic compound GdPd2Bi

The present work aims to address the electronic and magnetic properties of the intermetallic compound GdPd$_2$Bi through a comprehensive study of the structural, magnetic, electrical and thermal transport on a polycrystalline sample, followed by theoretical calculations. Our findings indicate that the magnetic ground state is antiferromagnetic in nature. Magnetotransport data present prominent hysteresis loop hinting a structural transition with further support from specific heat and thermopower measurements, but no such signature is observed in the magnetization study. Temperature dependent powder x-ray diffraction measurements confirm martensitic transition from the high-temperature (HT) cubic Heusler $L2_1$ structure to the low-temperature (LT) orthorhombic $Pmma$ structure similar to many previously reported shape memory alloys. The HT to LT phase transition is characterized by a sharp increase in resistivity associated with prominent thermal hysteresis. Further, we observe robust Bain distortion between cubic and orthorhombic lattice parameters related by $a_{orth} = \sqrt{2}a_{cub}$, $b_{orth} = a_{cub}$ and $c_{orth} = a_{cub}/\sqrt{2}$, that occurs by contraction along $c$-axis and elongation along $a$-axis respectively. The sample shows an unusual `non-saturating' $H^2$-dependent negative magnetoresistance for magnetic field as high as 150 kOe. In addition, non-linear field dependence of Hall resistivity is observed below about 30 K, which coincides with the sign change of the Seebeck coefficient. The electronic structure calculations confirm robust metallic states both in the LT and HT phases. It indicates complex nature of the Fermi surface along with the existence of both electron and hole charge carriers. The anomalous transport behaviors can be related to the presence of both electron and hole pockets.

cond-mat.str-el↗