Quantum Fluctuations and Entanglement in High-Tc Superconductors

This project aims at experimentally investigating the strange metal phase of the cuprate high-TCsuperconductor YBa2Cu3O7-x  through transport measurements in nanodevices.

Understanding the physics underlying the highly non-Fermi liquid like behavior in the strange metal phase might hold the key in identifying the mechanism leading to the high superconducting transition temperatures in these materials.

The strange metal phase is believed to emerge from a quantum critical point as a quantum critical phase, which embodies a new state of matter entailing a large-scale entanglement among all constituents.

We will probe the strange metal phase for turbulent charge flow on the nanoscale, a very straightforward and concise prediction of the holographic duality approach, which is used to describe densely long-range entangled quantum matter.

The occurrence of turbulent charge flow on the nanoscale would be the “smoking gun” proof of this new type of quantum matter.In the superconducting state we will look for the existence of diverging length and time scales in the vicinity of the putative quantum critical point through measurements of spatio-temporal fluctuations of the superfluid stiffness.The project builds on our longstanding expertise in nano fabrication and transport characterization of High-TC devices in a wide temperature (down to mK) and frequency (up to 40 GHz) range.