D-PHYS News

Researchers from the Institute for Quantum Electronics and the Quantum Center studied particle and entropy flows between two connected superfluid reservoirs and found unexpected evidence of irreversible and enhanced entropy transport.

A team including researchers from the Department of Physics at ETH Zurich found a method for creating electrically defined quantum dots with the potential for long-sought tunability and scalability.

No two lecturers are likely to teach quantum mechanics in the same way, but many will agree that its richness and intrinsic peculiarities make for a wonderful playground for teaching experimentation.

Researchers in the Laboratory for Solid State Physics at ETH Zurich found evidence that bilayer graphene quantum dots may host a promising new type of quantum bit based on so-called valley states.

Researchers studied how quantum many-body scars, states that resist thermalisation, could be probed experimentally in a variety of systems and thus harnessed for quantum information processing applications.

Researchers from the Institute for Theoretical Physics used a more general formulation of quantum mechanics to study a breakdown of adiabaticity.

On 2 and 3 September up to 30,000 visitors sought answers to the question: what holds the world together?

Thanks to a collaboration between the Department of Physics at ETH Zurich and Technorama, visitors to the Science Centre can see with their naked eye very small objects that behave according to the unfamiliar laws of quantum mechanics – single atoms.

Researchers at ETH have put a crystal into a quantum superposition state and measured for how long quantum effects in the vibrations of the crystal lasted. Such measurements are important for putting bounds on possible modifications of quantum theory that could explain why we do not see quantum features in everyday life.

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.

EPFL researchers have collaborated with colleagues at ETH Zurich and Harvard University on a new thin-film circuit which, when connected to a laser beam, produces finely tailorable terahertz-frequency waves. The device opens up a world of potential applications in optics and telecommunications.

ETH physicists demonstrate how atoms can be pumped through a synthetic crystal without having to apply external periodic driving. These experiments combine several key aspects of quantum many-body physics in unexpected ways, thus paving a novel path to understanding and creating exotic states of quantum matter.

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.

Systems in which mechanical motion is controlled at the level of individual quanta are emerging as a promising quantum-technology platform. New experimental work now establishes how quantum properties of such systems can be measured without destroying the quantum state — a key ingredient for tapping the full potential of mechanical quantum systems.

It is well established that quantum error correction can improve the performance of quantum sensors. But new theory work cautions that, unexpectedly, the approach can also give rise to inaccurate and misleading results — and shows how to rectify these shortcomings.

A hallmark of so-called topological quantum states is that they are protected against local perturbations. ETH physicists now demonstrate that in the paradigmatic case of the integer quantum Hall effect, vacuum fluctuations can cause a breakdown of topological protection.

ETH physicists have modified one of the major schemes for quantum error correction and put it into practice, demonstrating that they can substantially prolong the lifetime of quantum states — a crucial ingredient for future large-scale quantum computers.

Quantum computers and quantum mechanics are currently the focus of intensive research, including at ETH Zurich, and are also increasingly becoming topics in the media. In this domain, researchers work with the tiniest of particles daily, with a particular emphasis on experimentally realizing a new era of information technologies with capabilities beyond those available to us today. But how can this world of quantum physics be experienced outside the laboratory?

Eugene Demler, quantum researcher and professor at ETH Zurich, was honoured for his theoretical work on quantum fluids and solids, especially for his contributions to the study of ultracold atoms in optical lattices.

ETH professor Renato Renner is one of the world’s leading theoreticians in quantum information science. He talks about the latest developments. Renato Renner’s group focuses on the question of how the processing and transmission of information relates to physical laws.

Yiwen Chu researches new ways of connecting quantum technologies, with the aim of creating a quantum telecommunications network for the exchange and storage of quantum information.

ETH has once again been highly successful in the awarding of this year’s ERC Starting Grants for young researchers, with the European Research Council (ERC) approving a total of CHF 21.4 million in funding for 12 ETH project submissions, among them those of physicists Yiwen Chu and Judit Szulágyi.

In combined theoretical and experimental work, ETH physicists introduce and demonstrate a novel mechanism for electron optics in two-dimensional solid-state systems. The discovery opens up a route to engineering quantum-optical phenomena in a variety of materials and devices.

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.

Well-controlled shuttling of ions through laser beams should enable scalable quantum computing.