Research Highlights

Experimentalists at the Max Planck Institute of Quantum Optics in Garching (Germany), in close collaboration with theoretical physicist Eugene Demler at ETH Zurich, observed for the first time in microscopic detail how magnetic correlations mediate the pairing of quantum entities known as holes. The work establishes an intriguing platform for exploring theoretical models of high-temperature superconductivity — and might guide future efforts for designing novel quantum materials.

A method known as quantum key distribution has long held the promise of communication security unattainable in conventional cryptography. An international team of scientists, including ETH physicists, has now demonstrated experimentally, for the first time, an approach to quantum key distribution that uses high-quality quantum entanglement to provide much broader security guarantees than previous schemes.

How can we protect communications against 'eavesdropping' if we don’t trust the devices used in the process? This is one of the main questions in quantum-cryptography research. Researchers at the University of Basel and ETH Zurich have now developed the theoretical groundwork for a communication protocol that guarantees one hundred percent privacy.

Combined theoretical and experimental work unveils a novel mechanism through which criticality emerges in quasiperiodic structures — a finding that provides unique insight into the physics on the middle ground between order and disorder.

A concept known as ‘fragile topology’ has been puzzling physicists ever since it emerged two years ago. Two teams, one led by ETH physicists, have now developed a comprehensive theoretical and experimental framework to pin down the essence of the concept — and establish ways how to potentially harness it in applications.

Quasiparticles that behave like massless fermions, known as Weyl fermions, have been in recent years at the centre of a string of exciting findings in condensed matter physics. The group of Sebastian Huber at ETH Zurich now reports experiments in which they got a handle on one of the defining properties of Weyl fermions — their chirality

An international team including two ETH physicists has demonstrated that algorithms and hardware developed originally in the context of quantum computation can be harnessed for quantum-enhanced sensing of magnetic fields.

Two physicists at ETH Zurich and the Hebrew University of Jerusalem have developed a novel machine-learning algorithm that analyses large data sets describing a physical system and extract from them the essential information needed to understand the underlying physics.

In a world in which we use devices that we do not necessarily trust, can there be any privacy? Yes, and that's precisely what device-independent quantum cryptography achieves. New work now shows how this ‘ultimate’ level of communication security could be reached in practise.

In the current issue of the journal Nature Physics, ETH physicists Oded Zilberberg and Sebastian Huber describe unexpected connections between physics and the mathematical field of topology. With their pieces they provide intriguing outlooks on two aspects of ‘topological matter’ — a field of great current interest, and one to which physicists at ETH Zurich have contributed substantially over the years.