Observation of the electronic Pomeranchuk effect in generalized Wigner crystals of twisted MoS$_2$

Xinjie Fang; Linfeng Wu; Naitian Liu; Le Zhang; Wenqiang Zhou; Jing Ding; Zhangyuan Chen; Hanxiao Xiang; Yue Xiao; Kenji Watanabe; Takashi Taniguchi; Shuigang Xu

arXiv · 2609.30788

Observation of the electronic Pomeranchuk effect in generalized Wigner crystals of twisted MoS$_2$

Xinjie Fang·Linfeng Wu·Naitian Liu·Le Zhang·Wenqiang Zhou·Jing Ding·Zhangyuan Chen·Hanxiao Xiang·Yue Xiao·Kenji Watanabe·Takashi Taniguchi·Shuigang Xu

View original source ↗Read source document ↗Export metadata ↓

Abstract

Moire superlattices in transition metal dichalcogenides provide a highly tunable platform for exploring strongly correlated electronic phases, such as generalized Wigner crystals. While these crystalline states typically melt with increasing thermal fluctuations, an electronic analogue of the Pomeranchuk effect can stabilize the localized solid phase at elevated temperature through isospin entropy. Here, we report the observation of an electronic Pomeranchuk effect at the fractional filling factors of $ν= 1/3$ and $ν= 1/4$ in AB-stacked twisted bilayer MoS$_2$ with twist angles of 4.1$^\circ$ and 3.9$^\circ$, respectively. At ultra-low temperature, the system exhibits a highly conducting, itinerant behavior at these fractional fillings, characteristic of a compressible Fermi-liquid ground state. Upon heating, the system exhibits a counterintuitive increase in the longitudinal resistivity, signaling an isospin-entropy-driven transition into a localized generalized Wigner crystal state. Our findings highlight the unique capacity of flat bands in twisted bilayer MoS$_2$ for stabilizing highly degenerate magnetic configurations, offering new insights into the thermodynamic phase diagrams of low-dimensional correlated systems.

Explore related subjects

cond-mat.mes-hall cond-mat.mtrl-sci cond-mat.str-el

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

Xinjie Fang, Linfeng Wu, Naitian Liu, Le Zhang, Wenqiang Zhou, Jing Ding, Zhangyuan Chen, Hanxiao Xiang, Yue Xiao, Kenji Watanabe, Takashi Taniguchi, Shuigang Xu. 2026-09-25. Observation of the electronic Pomeranchuk effect in generalized Wigner crystals of twisted MoS$_2$. https://arxiv.org/abs/2609.30788

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Pomeranchuk-like electronic localization above 100 K in twisted MoS$_{2}$

Twisted transition-metal dichalcogenides (TMDs) have manifested a rich variety of emerging physical phenomena, yet experimental studies have so far been largely limited in their valence bands (p-doped). Here, we show correlated electronic states in the conduction bands (n-doped) of near-AA-twisted bilayer MoS$_2$ with twist angles ranging from $\sim2.3^\circ$ to $\sim3.5^\circ$, down to the mK temperature regime. A strongly reconstructed correlated phase diagram as a function of twist-angle has been observed - correlated gaps persist to temperatures approaching $160$ K at small twist angles, but collapse to only $\sim20$ K at intermediate angles, where a richer landscape of interaction-driven states emerges. At the largest twist-angle $\sim 3.5\,^{\circ}$, correlated resistance at 1 electron per moiré unit cell is enhanced upon heating, consistent with thermally assisted localization, or, a Pomeranchuk-like behaviour. Its magnetic-field response, however, is highly anisotropic, which differs markedly from that of canonical isospin moiré Pomeranchuk effect in graphene systems. Strikingly, such signature can persist even above 100 K around a filling of 2 electrons per moiré, despite of its weak resistive nature. Our results establish the twisted MoS$_2$ as a platform for studying the complexity of charge localization, internal flavour degrees of freedom, and band topology in conduction bands of semiconducting moiré systems.

cond-mat.mes-hall↗

arXiv2026

Electrically controlled spin-splitting and asymmetric tunnel magnetoresistance in anti-altermagnets

Anti-altermagnets (AAMs) are a recently identified class of layered magnetic materials where opposite spin-splitting in adjacent layers creates a globally spin-degenerate band structure, rendering conventional spectroscopic detection highly difficult. In this paper, we theoretically demonstrate an all-electrical method to manipulate and probe this hidden magnetic order using a dual-gated transport junction. By applying a perpendicular displacement field, we break the spatial inversion symmetry of the lattice, explicitly lifting the global spin degeneracy. We attach ferromagnetic (FM) leads on either side of the AAM. Using quantum transport calculations, we show that this gate-induced spin-splitting manifests as a strongly asymmetric tunnel magnetoresistance (TMR) as a function of the lead magnetization. We identify specific crystallographic orientations where the TMR retains its symmetry despite the fully split bands, a direct consequence of exact momentum-space compensation. We further reveal that Rashba spin-orbit coupling guarantees robust, highly directional transport asymmetries even in the absence of an explicit chemical potential mismatch between the layers. Our findings establish a clear, electrically tunable framework for exploiting AAMs in next-generation spintronic architectures.

cond-mat.mes-hall↗

arXiv2026

Surface effects on the plasmons in two-dimemsional heterostructures: Application to tilted semi-Dirac materials

We derived closed-form analytic expressions for the plasmon dispersion equations for two and three monolayers embedded in a non-uniform dielectric medium with a surface. There is no electron tunneling between the layers or hybridization of the layer polarizability. The dispersion equations are deduced from calculated expressions for the corresponding surface response functions (SRFs) generated by a frequency-dependent external polarized electromagnetic field. The SRF is calculated by employing Maxwell's equations in conjunction with linear response theory.The dispersion functions reduce to well-known results for two and three monolayers embedded in a bulk medium with a uniform dielectric background. We examine the role played by a surface (i.e., homogeneous versus inhomogeneous dielectric background screening), for gapped tilted semi-Dirac materials (TSDMs) with half-linear, half-parabolic spectrums whose energy bands are tilted, anisotropic in wave vector space, and a gap is induced. The number of plasmon branches is always equal to the number of monolayer. However, the separation between these branches depends on the distance between the layers and crucially on the chosen dielectric material between the layers and whether there is air or a substrate surrounding the layered structure. For gapped TSDM, the Landau damping, i.e., Plasmon lifetime, varies from branch to branch as well as along the branch for a chosen wave vector direction. We examine these novel behaviors for two and three gapped TSDM monolayers assuming different values for the dielectric background. Our results could be useful for comparing theory with experimental data from electron energy loss spectroscopy (EELS) data.

cond-mat.mes-hall↗