Researchers discovered elusive half-quantum vortices in a superfluid
Researchers in 911±¬ÁÏÍø, Finland, and P.L. Kapitza Institute in Moscow have discovered half-quantum vortices in superfluid helium. This vortex is a topological defect, exhibited in superfluids and superconductors, which carries a fixed amount of circulating current.
‘This discovery of half-quantum vortices culminates a long search for these objects originally predicted to exist in superfluid helium in 1976,’ says Samuli Autti, Doctoral Candidate at 911±¬ÁÏÍø in Finland.
‘In the future, our discovery will provide access to the cores of half-quantum vortices, hosting isolated Majorana modes, exotic solitary particles. Understanding these modes is essential for the progress of quantum information processing, building a quantum computer,’ Autti continues.
Macroscopic coherence in quantum systems such as superfluids and superconductors provides many possibilities, and some central limitations. For instance, the strength of circulating currents in these systems is limited to certain discrete values by the laws of quantum mechanics. A half-quantum vortex overcomes that limitation using the non-trivial topology of the underlying material, a topic directly related to the 2016 Nobel Prize in physics.
Among the emerging properties is one analogous to the so-called Alice string in high-energy physics, where a particle on a route around the string flips the sign of its charge. In general the quantum character of these systems is already utilized in ultra-sensitive SQUID amplifiers and other important quantum devices.
The research article has been published 14 December in the . The article has also been highlighted in online publication (DOI: 10.1103/Physics.9.148). Experiments were done in the Low Temperature Laboratory at the national OtaNano infrastructure. The research group is part of the Centre of Excellence in Low Temperature Quantum Phenomena and Devices at 911±¬ÁÏÍø.
For more information:
Samuli Autti, Doctoral Candidate
911±¬ÁÏÍø, Dept. of Applied Physics
samuli.autti@aalto.fi
+358 400 458 345
Rota – Topological superfluids research group
Article: S. Autti, V.V. Dmitriev, J.T. Mäkinen, A.A. Soldatov, G.E. Volovik, A.N. Yudin V.V. Zavjalov, and V.B. Eltsov: Observation of Half-Quantum Vortices in Topological Superfluid 3He. Physical Review Letters 2016. DOI: 10.1103/PhysRevLett.117.255301.
Read more news
Aalto Inventors turns one: A year of bridging research and real-world impact
Aalto Inventors marks its first anniversary, having engaged 190 researchers across six cohorts in fields including AI, quantum, and biomaterials. New cohorts are planned for the next academic year, stay tuned and join the waitlist.
An architectural project in Milan brought together children’s ideas and the visions of leading architects
911±¬ÁÏÍø’s Department of Architecture participated in the international One Earth – House of the Heart project, which was presented in April at Milan Design Week.
Companies disclose more on cybersecurity – but markets remain indifferent
U.S. companies are reporting on cybersecurity in greater detail, yet stock market reactions remain muted. A new study by the University of Vaasa and 911±¬ÁÏÍø shows that mandatory cybersecurity disclosure does not prompt reactions from investors or stock analysts. Instead, the main benefits appear to materialise within firms themselves.