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Evolution of the Berry curvature dipole in uniaxially strained bilayer graphene
by Karel Cuypers, Robin Smeyers, Bert Jorissen, Lucian Covaci
Submission summary
| Authors (as registered SciPost users): | Lucian Covaci |
| Submission information | |
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| Preprint Link: | https://arxiv.org/abs/2601.05962v1 (pdf) |
| Date submitted: | Jan. 12, 2026, 9:33 a.m. |
| Submitted by: | Lucian Covaci |
| Submitted to: | SciPost Physics Core |
| Ontological classification | |
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| Academic field: | Physics |
| Specialties: |
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| Approaches: | Theoretical, Computational |
Abstract
While in pristine bilayer graphene the Berry curvature dipole (BCD), a necessary ingredient for the nonlinear anomalous Hall effect, is zero, uniaxial strain can give rise to finite BCD. We investigate this by using a tight-binding (TB) approach build on the Slater-Koster parameterization to capture lattice deformation effects often missed by continuum models. We demonstrate that the BCD's evolution with strain and doping is highly sensitive to the choice in parameterization, particularly when including the longer range interlayer skew hoppings. Additionally, out-of-plane compression enhances the response by broadening the Dirac cones. These findings benchmark low-energy continuum models and highlight the necessity of realistic tight-binding models for accurately predicting strain-engineered Hall effects in bilayer graphene.
Current status:
Reports on this Submission
Report
In the manuscript “Evolution of the Berry curvature dipole in uniaxially strained bilayer graphene” (arXiv:2601.05962), the authors investigate the evolution of the Berry curvature dipole in AB-stacked bilayer graphene under various uniaxial strain configurations, using a tight-binding approach. While the topic is of potential interest, I have several concerns regarding the clarity and substantiation of the analysis.
I find Eqs. (4) and (5) confusing. In Eq. (4), the $x$ coordinates appears as $-1 + \epsilon_x$, whereas I would expect it to be written as $- (1 + \epsilon_x)$. The same issue arises in Eq. (5).
- The authors state that the effective continuum model becomes invalid at large strain, but this claim is not supported by quantitative evidence. No numerical estimates, plots, or systematic comparisons are provided to demonstrate the breakdown of the continuum description. Moreover, no physical explanation is given for why the continuum model fails in this regime. For instance, the continuum theory employed (Eq.~10) appears to include only linear-in-strain effects (e.g., a strain-induced pseudo–vector potential). It is therefore unclear whether the observed discrepancy arises from an intrinsic limitation of the continuum approach or simply from the neglect of higher-order (quadratic or beyond) strain terms. As it stands, the manuscript presents this conclusion as an assertion rather than a well-supported result.
Given these issues, particularly the lack of clarity in the formulation and the insufficient justification for the claimed breakdown of the continuum model, I cannot recommend the manuscript for publication in SciPost Physics Core in its current form.
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