Gespeichert in:
| Hauptverfasser: | , |
|---|---|
| Format: | Preprint |
| Veröffentlicht: |
2025
|
| Schlagworte: | |
| Online-Zugang: | https://arxiv.org/abs/2501.17616 |
| Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
| _version_ | 1866912624438935552 |
|---|---|
| author | Tomlins, Harry Tomczak, Jan M. |
| author_facet | Tomlins, Harry Tomczak, Jan M. |
| contents | We study the charge transport across a band-tuned metal-insulator transition in two dimensions. For high temperatures $T$ and chemical potentials $μ$ far from the transition point, conduction is ballistic and the resistance $R(T)$ verifies a simple one-parameter scaling relation. Here, we explore the limits of this semi-classical behaviour and study the quantum regime beyond, where scaling breaks down. We derive an analytical formula for the simplest Feynman diagram of the linear-response conductivity $σ=1/R$ of a parabolic band endowed with a finite lifetime. Our formula shows excellent agreement for experiments for a field-tuned MoTe$_2$/WSe$_2$ moiré bilayer, and can capture the quantum effects responsible for breaking the one-parameter scaling. We go on to discuss a fascinating prediction of our model: The resistance at the quantum-critical band-tuned Lifshitz point ($μ=T=0$) has the universal value, $R_L=(2 πh)/e^2$, per degree of freedom and this value is found to be compatible with experiment. Furthermore, we investigate whether two dimensional metal-insulator transitions driven by strong electron correlations or disorder can also be classified by their quantum-critical resistance and find that $R_L$ may be useful in identifying predominantly interaction driven transitions. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2501_17616 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Universal transport at Lifshitz metal-insulator transitions in two dimensions Tomlins, Harry Tomczak, Jan M. Strongly Correlated Electrons We study the charge transport across a band-tuned metal-insulator transition in two dimensions. For high temperatures $T$ and chemical potentials $μ$ far from the transition point, conduction is ballistic and the resistance $R(T)$ verifies a simple one-parameter scaling relation. Here, we explore the limits of this semi-classical behaviour and study the quantum regime beyond, where scaling breaks down. We derive an analytical formula for the simplest Feynman diagram of the linear-response conductivity $σ=1/R$ of a parabolic band endowed with a finite lifetime. Our formula shows excellent agreement for experiments for a field-tuned MoTe$_2$/WSe$_2$ moiré bilayer, and can capture the quantum effects responsible for breaking the one-parameter scaling. We go on to discuss a fascinating prediction of our model: The resistance at the quantum-critical band-tuned Lifshitz point ($μ=T=0$) has the universal value, $R_L=(2 πh)/e^2$, per degree of freedom and this value is found to be compatible with experiment. Furthermore, we investigate whether two dimensional metal-insulator transitions driven by strong electron correlations or disorder can also be classified by their quantum-critical resistance and find that $R_L$ may be useful in identifying predominantly interaction driven transitions. |
| title | Universal transport at Lifshitz metal-insulator transitions in two dimensions |
| topic | Strongly Correlated Electrons |
| url | https://arxiv.org/abs/2501.17616 |