News
Coherent superpositions of three states for phosphorous donors in silicon prepared using THz radiation
Superposition of orbital eigenstates is crucial to quantum technology utilizing atoms, such as atomic clocks and quantum computers, and control over the interaction between atoms and their neighbours is an essential ingredient for both gating and readout. A team of researchers including Photon Science division head Gabriel Aeppli has demonstrated THz laser pulse control of Si:P orbitals using multiple orbital state admixtures, observing beat patterns produced by Zeeman splitting. The beats are an observable signature of the ability to control the path of the electron, which implies we can now control the strength and duration of the interaction of the atom with different neighbours. This could simplify surface code networks which require spatially controlled interaction between atoms. The full article can be read in Nature Communications
New quantum state observed in a Shastry–Sutherland compound
Scientists from PSI and the École polytechnique fédérale de Lausanne (EPFL) have shown experimentally, for the first time, a quantum phase transition in strontium copper borate, the only material to date that realizes the famous Shastry–Sutherland quantum many-body model.
Scientists get first direct look at how electrons ‘dance’ with vibrating atoms
Scientists at the SLAC National Accelerator Laboratory and Stanford University - one of the leading authors, Simon Gerber, has in the meantime relocated to PSI - have made the first direct measurements, and by far the most precise ones, of how electrons move in sync with atomic vibrations rippling through an quantum material, in the present study an unconventional superconductor, as if they were “dancing" to the same beat.
Nondestructive imaging of atomically thin nanostructures buried in silicon
A team of researchers including Photon Sciences division head Gabriel Aeppli have demonstrated the first non-destructive imaging of atomically thin nanostructures in silicon. Such structures are the building blocks of quantum devices for physics research and are likely to serve as key components of devices for next-generation classical and quantum information processing. Until now, the characteristics of buried dopant nanostructures could only be inferred from destructive techniques and/or the performance of the final electronic device; this severely limits engineering and manufacture of real-world devices based on atomic-scale lithography. In work recently published in Science Advances, the team use scanning microwave microscopy (SMM) to image and electronically characterize three-dimensional phosphorus nanostructures fabricated via scanning tunneling microscope based lithography.
Wafer-thin Magnetic Materials Developed for Future Quantum Technologies
For the first time, researchers have produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Paul Scherrer Institute, in collaboration with their research partners, published the findings in the journal Nature Communications.
Distinct, but not so different
Among superconducting materials, CeCoIn5 stands out as a rare case where superconductivity gives rise to magnetic order. An international team led by PSI physicist Michel Kenzelmann now reports that when small amounts of impurities are implanted into CeCoIn5, then two distinct magnetic phases appear — and these are surprisingly similar to one another.
A breakthrough on Weyl semimetals
In their recent paper, Distinct Evolutions of Weyl fermion quasiparticles and Fermi arcs with bulk band topology in Weyl semimetals, two MARVEL groups — led by Prof. Ming Shi and Dr Nan Xu at PSI for the experimental part, and with Prof. Oleg Yazyev and Dr Gabriel Autès at EPFL for the theoretical side — joined forces to shed light (and soft X-rays) on the relationship between the bulk band topology in Weyl semimetals and two measurable signatures of Weyl fermion quasiparticles: magneto-transport effects in the bulk, and Fermi arcs on the surface.
3-D X-ray imaging makes the finest details of a computer chip visible
Researchers at the PSI have made detailed 3-D X-ray images of a commercially available computer chip. In their experiment, they examined a small piece that they had cut out of the chip beforehand. This sample remained undamaged throughout the measurement. It is a major challenge for manufacturers to determine if, in the end, the structure of their chips conforms to the specifications. Thus these results represent one important application of an X-ray tomography method that the PSI researchers have been developing for several years.
Switzerland at the Quantum Crossroads document endorsed by QTC@PSI members
“Switzerland at the Quantum Crossroads” outlines the current quantum science and technology landscape in Switzerland, explains the promises of this technology and outlines the required steps for Switzerland to leverage its leadership in this space.