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arxiv: 2605.08228 · v1 · submitted 2026-05-06 · ❄️ cond-mat.mes-hall · cond-mat.mtrl-sci

Recognition: no theorem link

Rashba engineering at van der Waals interfaces

Adrien Michon, Alain Marty, Anupam Jana, Fatima Ibrahim, Federico Mazzola, Fr\'ed\'eric Bonell, Ga\'etan Verdierre, Gauthier Krizman, Henri Jaffr\`es, Isabelle Gomes de Moraes, Ivana Vobornik, Jean-Marie George, J\'er\^ome Tignon, Jing Li, Juliette Mangeney, Jun Fujii, Leticia Melo Costa, Libor Voj\'a\v{c}ek, Mairbek Chshiev, Martin Mi\v{c}ica, Matthieu Jamet, Nicola Marzari, Oliver Paull, Olivier Renault, Rahul Sharma, Soumya Mukherjee, Sukhdeep Dhillon, Sylvain Massabeau, Vincent Polewczyk

Pith reviewed 2026-05-12 00:45 UTC · model grok-4.3

classification ❄️ cond-mat.mes-hall cond-mat.mtrl-sci
keywords Rashba spin splittingvan der Waals heterobilayersTMD interfacesTHz spintronic emissionspin-to-charge conversionelectronic hybridizationin-gap states
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0 comments X

The pith

The interface between different TMD monolayers controls the sign and strength of Rashba spin splitting, enabling heterobilayers that outperform bulk materials in THz spintronic emission.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

This paper shows that stacking two different epitaxially grown TMD monolayers creates an interface whose electronic hybridization produces in-gap states carrying strong Rashba spin-orbit coupling. The authors use THz spintronic emission to demonstrate that the choice of layers sets both the intensity and the sign of the resulting spin splitting, with optimized pairs such as HfSe2/PtSe2 delivering higher spin-to-charge conversion than any single bulk TMD. A sympathetic reader cares because the result supplies a practical route to engineer spintronic response in van der Waals stacks rather than relying on the properties of one material alone.

Core claim

The interface between a large variety of two different epitaxially grown TMD monolayers controls the intensity and sign of the Rashba spin splitting, which is probed using THz spintronic emission. Optimized TMD heterobilayers, such as HfSe2/PtSe2, show enhanced THz emission that surpass the spin-to-charge conversion efficiency of bulk TMDs, confirming the presence of Rashba states with large spin splitting at the interface. By combining spin- and angle-resolved photoemission spectroscopy with density functional theory, we reveal that the electronic hybridization between the two different TMD monolayers gives rise to extended in-gap states with strong Rashba spin-orbit coupling. The choice of

What carries the argument

Electronic hybridization at the TMD heterobilayer van der Waals interface that generates extended in-gap states with large Rashba spin-orbit coupling.

Load-bearing premise

The enhanced THz emission and in-gap states are produced by interface hybridization and Rashba spin-orbit coupling rather than charge transfer, moiré patterns, or defects.

What would settle it

Quantitative agreement between the Rashba parameter measured by ARPES on the heterobilayer and the polarity plus amplitude of the THz emission signal predicted from the same band structure.

Figures

Figures reproduced from arXiv: 2605.08228 by Adrien Michon, Alain Marty, Anupam Jana, Fatima Ibrahim, Federico Mazzola, Fr\'ed\'eric Bonell, Ga\'etan Verdierre, Gauthier Krizman, Henri Jaffr\`es, Isabelle Gomes de Moraes, Ivana Vobornik, Jean-Marie George, J\'er\^ome Tignon, Jing Li, Juliette Mangeney, Jun Fujii, Leticia Melo Costa, Libor Voj\'a\v{c}ek, Mairbek Chshiev, Martin Mi\v{c}ica, Matthieu Jamet, Nicola Marzari, Oliver Paull, Olivier Renault, Rahul Sharma, Soumya Mukherjee, Sukhdeep Dhillon, Sylvain Massabeau, Vincent Polewczyk.

Figure 1
Figure 1. Figure 1: FIG. 1 [PITH_FULL_IMAGE:figures/full_fig_p005_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: FIG. 2 [PITH_FULL_IMAGE:figures/full_fig_p007_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: FIG. 3 [PITH_FULL_IMAGE:figures/full_fig_p009_3.png] view at source ↗
Figure 4
Figure 4. Figure 4: FIG. 4 [PITH_FULL_IMAGE:figures/full_fig_p011_4.png] view at source ↗
Figure 5
Figure 5. Figure 5: FIG. 5 [PITH_FULL_IMAGE:figures/full_fig_p014_5.png] view at source ↗
read the original abstract

Two-dimensional transition metal dichalcogenide (TMD) interfaces offer a versatile platform for studying emergent quantum phenomena and enabling novel device functionalities. When distinct TMD monolayers are stacked vertically or laterally stitched, their interfaces can exhibit unique electronic band alignments, giving rise to long-lived interlayer excitons, charge transfer effects, and moir\'e superlattices with correlated states. Here, we demonstrate that the interface between a large variety of two different epitaxially grown TMD monolayers controls the intensity and sign of the Rashba spin splitting, which is probed using THz spintronic emission. Optimized TMD heterobilayers, such as HfSe$_2$/PtSe$_2$, show enhanced THz emission that surpass the spin-to-charge conversion efficiency of bulk TMDs, confirming the presence of Rashba states with large spin splitting at the interface. By combining spin- and angle-resolved photoemission spectroscopy with density functional theory, we reveal that the electronic hybridization between the two different TMD monolayers gives rise to extended in-gap states with strong Rashba spin-orbit coupling. The choice of TMD layers enables to engineer the sign and strength of spin-to-charge conversion in van der Waals heterobilayers opening up perspectives to build efficient and tunable THz spintronic emitters.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

1 major / 2 minor

Summary. The manuscript investigates Rashba spin splitting at van der Waals interfaces of epitaxially grown TMD heterobilayers. It claims that stacking different TMD monolayers allows engineering of the sign and intensity of Rashba splitting, demonstrated by enhanced THz spintronic emission in heterobilayers such as HfSe2/PtSe2 that surpasses bulk TMD efficiency. This is attributed to electronic hybridization producing extended in-gap states with strong SOC, as revealed by SARPES and DFT calculations. The work positions these interfaces as tunable platforms for spin-to-charge conversion in THz emitters.

Significance. If substantiated, the results would provide a versatile route to engineer Rashba effects in 2D vdW systems beyond bulk materials, with direct implications for efficient, tunable THz spintronic devices. The multi-technique approach (THz emission, SARPES, DFT) and demonstration of layer-choice tunability are positive aspects that could advance the field of interface spintronics.

major comments (1)
  1. Abstract: The claim that enhanced THz emission in HfSe2/PtSe2 'surpass[es] the spin-to-charge conversion efficiency of bulk TMDs, confirming the presence of Rashba states with large spin splitting' is load-bearing but lacks a quantitative correlation. The Rashba parameter α_R extracted from SARPES and DFT must be directly compared to the inverse Rashba-Edelstein length inferred from the THz data; without this match and explicit single-layer controls, alternatives such as interfacial charge transfer, moiré potentials, or defects cannot be ruled out as the origin of the observed effects.
minor comments (2)
  1. Abstract: The phrasing 'a large variety of two different epitaxially grown TMD monolayers' is unclear and should be reworded for precision (e.g., 'various pairs of epitaxially grown TMD monolayers').
  2. Ensure all experimental figures (THz emission, SARPES) include error bars, sample statistics, and details on background subtraction to strengthen the 'enhanced' and 'surpass' claims.

Simulated Author's Rebuttal

1 responses · 0 unresolved

We thank the referee for their positive evaluation of the significance of our work and for the detailed, constructive comment. We have carefully addressed the concern regarding the abstract claim and the need for quantitative correlation between techniques.

read point-by-point responses
  1. Referee: Abstract: The claim that enhanced THz emission in HfSe2/PtSe2 'surpass[es] the spin-to-charge conversion efficiency of bulk TMDs, confirming the presence of Rashba states with large spin splitting' is load-bearing but lacks a quantitative correlation. The Rashba parameter α_R extracted from SARPES and DFT must be directly compared to the inverse Rashba-Edelstein length inferred from the THz data; without this match and explicit single-layer controls, alternatives such as interfacial charge transfer, moiré potentials, or defects cannot be ruled out as the origin of the observed effects.

    Authors: We agree that a direct quantitative comparison would strengthen the manuscript. In the revised version we will extract the inverse Rashba-Edelstein length from the THz emission amplitudes and explicitly compare it to the α_R values obtained from SARPES and DFT for the same HfSe2/PtSe2 interface. We will also add a dedicated paragraph and supplementary figures comparing the heterobilayer results to single-layer TMD controls (where available from our growth and measurement campaigns) to help exclude charge-transfer or defect-dominated scenarios. While moiré potentials cannot be entirely excluded without additional microscopy, the observed sign reversal of the THz signal upon layer swapping and the appearance of extended in-gap states with strong SOC in our DFT calculations are signatures that are difficult to reconcile with moiré or simple charge-transfer pictures alone. We will tone down the abstract wording to reflect that the interface Rashba states are the most consistent explanation supported by the multi-technique data. revision: yes

Circularity Check

0 steps flagged

No significant circularity; claims rest on independent experiments and standard DFT

full rationale

The paper's derivation chain consists of experimental observations (THz spintronic emission exceeding bulk TMD controls, SARPES spectra) interpreted via standard DFT band-structure calculations showing hybridization-induced in-gap states. No load-bearing step reduces a prediction to a fitted input by construction, invokes a self-citation uniqueness theorem, or renames a known result as new unification. The sign and strength engineering is directly tied to measured emission polarity and DFT orbital character without self-referential definitions or ansatzes smuggled via prior work. This is the normal case of a self-contained experimental-computational study.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 0 invented entities

The central claim relies on experimental observations and standard computational methods without introducing new free parameters or entities.

axioms (1)
  • standard math Standard density functional theory approximations for electronic structure calculations
    Used to interpret hybridization and Rashba states from SARPES data.

pith-pipeline@v0.9.0 · 5659 in / 1320 out tokens · 64607 ms · 2026-05-12T00:45:37.523079+00:00 · methodology

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Reference graph

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