Black Holes, Quantum Systems, Superconductors and Planck’s Constant are Related

Researchers from the CNRS and Université de Sherbrooke, have discovered a universal law for the electronic properties of high-temperature superconductors. They exposed superconductors to an intense magnetic field to weaken superconductivity and reveal underlying properties. They measured the variations of electrical resistivity up to -263 °C, and developed a predictive model that can be applied to multiple families of high-temperature superconductors.

This energy dissipation speed limit is linked to the numerical value of Planck’s constant, the fundamental quantity of quantum mechanics representing the smallest possible action that can be taken in nature.

Natalie Wolchover writing at the Atlantic describes how superconducting research could be near conceptual breakthroughs in understanding the physics of superconductors. There appears to be holographic duality that mathematically connects systems of scrambled quantum particles, like those in strange metals, to imaginary black holes in one higher dimension.

Black holes, quantum systems, superconductors and Planck’s constant appear to be related.

Nature Physics – Universal T-linear resistivity and Planckian dissipation in overdoped cuprates

Electrons inside a variety of ceramic crystals of cuprate superconductors seem to dissipate energy as quickly as possible, apparently bumping up against a fundamental quantum speed limit. Older studies found that other exotic superconducting compounds—strontium ruthenates, pnictides, tetramethyltetrathiafulvalenes also burn energy at what appears to be a maximum allowed rate.

Abstract – Universal T-linear resistivity and Planckian dissipation in overdoped cuprates

The perfectly linear temperature dependence of the electrical resistivity observed as T → 0 in a variety of metals close to a quantum critical point is a major puzzle of condensed-matter physics. Here we show that T-linear resistivity as T → 0 is a generic property of cuprates, associated with a universal scattering rate. We measured the low-temperature resistivity of the bilayer cuprate Bi2Sr2CaCu2O8+δ and found that it exhibits a T-linear dependence with the same slope as in the single-layer cuprates Bi2Sr2CuO6+δ, La1.6−xNd0.4SrxCuO4 and La2−xSrxCuO4, despite their very different Fermi surfaces and structural, superconducting and magnetic properties. We then show that the T-linear coefficient (per CuO2 plane), A1□, is given by the universal relation A1□TF = h/2e2, where e is the electron charge, h is the Planck constant and TF is the Fermi temperature. This relation, obtained by assuming that the scattering rate 1/τ of charge carriers reaches the Planckian limit whereby ħ/τ = kBT, works not only for hole-doped cuprates but also for electron-doped cuprates despite the different nature of their quantum critical point and strength of their electron correlations.