To measure the quantum order throughout this classically disordered liquid, the scientists used neutrons to image the magnetic excitations - “flips” or fluctuations of the spins - and the distances over which they could propagate. The experiments were performed at the National Institute of Standards and Technology (NIST) Center for Neutron Research in the US and at the ISIS particle accelerator of the Rutherford Appleton Laboratory in the UK.
The scientists found that despite the apparent classical disorder, magnetic excitations could propagate over long chains of atoms at low temperature - in the otherwise magnetically disordered material.
Other examples of large-scale quantum phase coherence include superconductors and superfluids where quantum physics leads to fascinating properties.
The team also discovered that they could limit the coherence or make it disappear altogether by introducing defects into the material either by adding chemical impurities (doping) or heating. These defects break the chains into independent sub-chains, each with its own, hidden order. This part of the reported research is the first step towards engineered spin-based quantum states in ceramics.
Aeppli and other members of the team note that their work was initially not intended to have direct applications, but that they later realized that what they are learning could be applied in a range of fields from nanotechnology to quantum computing.
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Collaborators on this research include: Guangyong Xu, of John Hopkins University and Brookhaven National Laboratory; Collin L. Broholm, Ying Chen, and Michel Kenzelmann of Johns Hopkins University and the NIST Center for Neutron Research; Yeong-Ah Soh of Dartmouth College; Gabriel Aeppli of the London Centre for Nanotechnology and University College London; John. F. DiTusa of Louisiana State University; Christopher D. Frost from the ISIS Facility, Rutherford Appleton Laboratory, U.K.; Toshimitsu Ito and Kunihiko Oka of the National Institute of Advanced Industrial Science and Technology (AIST), Japan; and Hidenori Takagi from AIST and University of Tokyo.
The work was funded by the Office of Basic Energy Sciences within the U.S. Department of Energy’s Office of Science, the National Science Foundation, a Wolfson-Royal Society Research Merit Award (UK), and by the Basic Technologies programme of the UK Research Councils.
Notes for editors:
Images:
Hi-res images are available from the Press Office.
Image 1
Image of quantum order made using neutrons by the LCN (London Centre for Nanotechnology)/UCL team and its collaborators from the US and Japan at the ISIS particle accelerator in the UK. The sharp red peak in the middle of the picture corresponds to nearly perfect quantum coherence or order.
Image 2
Nickel oxide chains which host quantum order in the YBaNiO5 oxide ceramic studied.
About the London Centre for Nanotechnology
The London Centre for Nanotechnology is a joint enterprise between UCL (University College London) and Imperial College London. In bringing together world-class infrastructure and leading nanotechnology research activities, the Centre aims to attain the critical mass to compete with the best facilities abroad. Furthermore by acting as a bridge between the biomedical, physical, chemical and engineering sciences the Centre will cross the 'chip-to-cell interface' - an essential step if the UK is to remain internationally competitive in biotechnology.
Website: www.london-nano.com
About UCL
Founded in 1826, UCL was the first English university established after Oxford and Cambridge, the first to admit students regardless of race, class, religion or gender, and the first to provide systematic teaching of law, architecture and medicine. In the government’s most recent Research Assessment Exercise, 59 UCL departments achieved top ratings of 5* and 5, indicating research quality of international excellence.
UCL is the fourth-ranked UK university in the 2006 league table of the top 500 world universities produced by the Shanghai Jiao Tong University. UCL alumni include Mahatma Gandhi (Laws 1889, Indian political and spiritual leader); Jonathan Dimbleby (Philosophy 1969, writer and television presenter); Junichiro Koizumi (Economics 1969, Prime Minister of Japan); Lord Woolf (Laws 1954, Lord Chief Justice of England & Wales); Alexander Graham Bell (Phonetics 1860s, inventor of the telephone), and members of the band Coldplay.
Website: www.ucl.ac.uk
About Research Councils UK
The seven Research Councils are independent non-departmental public bodies, funded by the Science Budget through the Office of Science and Innovation. They are incorporated by Royal Charter and together manage a research budget of over £2.8 billion a year.
Research Councils UK (RCUK) is the partnership between the UK's seven Research Councils. Through RCUK, the Research Councils work together to champion the research, training and innovation they support.
The seven UK Research Councils are: Arts & Humanities Research Council (AHRC) Biotechnology & Biological Sciences Research Council (BBSRC) Economic & Social Research Council (ESRC) Engineering & Physical Sciences Research Council (EPSRC) Medical Research Council (MRC) Natural Environment Research Council (NERC) Science and Technology Facilities Council (STFC) |
