'Sudden Death' Discovery Defies Our Understanding of Superconductivity

Spontaneous appearance of quantum fluctuations

Physicists from Princeton University and the Japanese National Institute for Materials Science have observed the spontaneous emergence of quantum fluctuations in atomically thin layers of insulating material.

This discovery was made during the examination of a point of transition from electron traffic-jam to superconducting freeway in a two-dimensional landscape.

The researchers were particularly interested in understanding how a superconducting phase can be changed to another phase.

The challenge of superconductivity

Superconductivity is the ideal state of conductivity where electrons can move effortlessly from start to finish, without any heat or wasted energy.

However, achieving superconductivity is not easy, as it requires electrons to lose their individuality and form Cooper pairs.

Researchers have been studying the triggers of this quantum transition and the role temperature plays, with the hope of achieving superconductivity at higher temperatures.

Quantum behavior on 2D surfaces

One area of research focuses on the quantum behavior of electrons on two-dimensional surfaces.

However, the lack of freedom to move up and down in these surfaces presents challenges in achieving superconductivity.

Strong fluctuations in lower dimensions often hinder the possibility of superconductivity.

These fluctuations are caused by quantum vortices, similar to eddies seen when draining a bathtub.

The 'sudden death' of fluctuations

The researchers conducted experiments on a single layer of the semi-metal tungsten ditelluride, observing the disappearance and reappearance of quantum vortices at specific electron densities.

Surprisingly, the vortices suddenly vanished at the critical electron density, which was unexpected.

This observation challenges current models and poses new questions about the behavior of superconductivity.