phénomène

supraconductivité induite par la lumière

Superconductivity triggered or enhanced by light exposure in atomic or quantum systems.
3 articles liés · 2 formules

Description

Light-induced superconductivity is a phenomenon where exposing certain materials to intense, brief pulses of light can temporarily make them superconduct — conduct electricity with zero resistance — at temperatures far above their normal transition point. This is not the same as conventional superconductivity, which requires cooling materials to extremely low temperatures; here, light energy briefly reorganizes the material's electrons into a paired state that flows without loss. The effect is particularly striking in materials like fullerenes (carbon spheres) and cuprates, where light can trigger superconductivity at or near room temperature, albeit only for picoseconds.

Histoire

The concept gained prominence in the 2010s, with experiments by Andrea Cavalleri's group at the Max Planck Institute for the Structure and Dynamics of Matter demonstrating light-induced superconductivity in cuprates and fullerenes. The specific mechanism for fullerenes was proposed and tested around 2023–2024.

Comment ça marche

In a superconductor, electrons form Cooper pairs that move coherently without scattering. Normally, this pairing is mediated by lattice vibrations (phonons) and only occurs at low temperatures. Light pulses can transiently excite the material's lattice or electronic structure, creating a new configuration where pairing is much stronger. For example, in fullerenes, mid-infrared light pulses can distort the molecular lattice, enhancing the coupling between electrons and phonons enough to allow pairing at higher temperatures. The effect is fleeting — the superconducting state decays within a few picoseconds — but it reveals pathways to room-temperature superconductivity that are inaccessible through static conditions.

En pratique

While the effect is too short-lived for direct technological use, it informs the search for materials that could sustain superconductivity at room temperature, potentially revolutionizing power transmission and magnetic levitation.

Anecdote

In some experiments, light pulses have induced superconductivity in fullerenes at temperatures as high as 100 K, which is about 40 K above their normal superconducting transition temperature.

Concept graph →

Formules

$$\beta_{\mathrm{app}} = \frac{\beta \sin\theta}{1 - \beta \cos\theta}$$
Apparent speed exceeding light due to relativistic projection.
Ce qu'il y a dans la formule
β_appvariableapparent transverse speed in units of c — apparent speed
βvariableactual speed in units of c — vitesse
θvariableangle between velocity and line of sight — angle radian
β_{{app}}=\frac{β\sinθ}{1-β\cosθ} · 2606.27430
β=\frac{β_{{app}}}{\sinθ+β_{{app}}\cosθ} · 2607.16104v1
$$\sigma = \sigma_0 \exp\left(-\frac{E_a}{k_B T}\right)$$
Conductivity depends exponentially on temperature and activation energy.
Ce qu'il y a dans la formule
\sigmavariableelectrical conductivity — electrical conductivity siemens per metre
\sigma_0variablepre-exponential factor (conductivity at infinite temperature) — electrical conductivity siemens per metre
E_avariableactivation energy for conduction — énergie joule
Tvariableabsolute temperature — température kelvin
k_BconstanteRelates temperature to energy in statistical mechanics. — constante de Boltzmann = 1.380649e-23 joule per kelvin
σ=σ_0\exp(-\frac{e_a}{k_bt}) · 2606.24480
p\propto\exp(-\frac{δg}{k_bt}) · 2606.24480
δf^*=k_bt\ln(τ/τ_0) · 2606.29055
k_s\approx\frac{δe_{{pv}}}{h}\exp(-\frac{g_{{rac}}}{rt}) · 2607.12813

Articles liés · 3

Optique2026-08-312 minarXiv:2608.30919
Capsule laser : une lumière qui éclate sur commande
Une minuscule capsule, semblable à une bulle de savon mais avec une coque de cristaux lumineux, se comporte comme un laser. Tant que sa paroi est intacte, la lumière circule en boucle, s'amplifie et jaillit en un faisceau étroit et brillant. Dès que la paroi éclate, le faisceau se transforme en une tache terne.
Physique quantique2026-02-042 minarXiv:2602.04627express
Lumière en chœur : comment une métasurface fait clignoter les atomes à l'unisson
La lumière émise par une multitude de minuscules émetteurs — atomes ou « points quantiques » artificiels — se disperse généralement dans toutes les directions, comme une foule où chacun crie pour soi. Mais si on les fait « chanter en chœur », l'éclat devient bien plus intense.
Supraconductivité2026-01-262 minarXiv:2601.18712express
La lumière rend des billes de carbone supraconductrices à température ambiante
Un supraconducteur ordinaire ne fonctionne que dans le congélateur de la nature : à des températures inférieures à moins cent degrés. Le matériau de billes de carbone K₃C₆₀ ne fait pas exception : sans froid, il résiste au courant comme une foule dans un couloir étroit.