ISIS Neutron and Muon Source Data Journal

The nature of excitations in a molecular Haldane system

Abstract: It is well known that an S = 1 antiferromagnetic spin chain is predicted to have a quantum disordered ground state and a gap in its excitation spectrum. This so-called Haldane gap is topological in origin and contrasts dramatically with the case for S = 1/2, whose topology leads to a gapless spectrum. We have recently synthesised an intriguing new series based on S = 1 NiX2(3,5-lutidine)4 molecular complexes formed from quasi-one-dimensional columns of Ni-X...X-Ni. In an experiment at PSI in 2017 we showed that NiI2(3,5-lutidine)4 remains disordered down to 30 mK, suggesting that the system is a highly successful realization of a Haldane chain system. We now plan to investigate the order and dynamics of the system in high field as we close the spin gap and drive the system through a quantum critical point (QCP) in a new experiment, only possible using the HIFI spectrometer at ISIS.

Principal Investigator: Professor Tom Lancaster
Experimenter: Professor Stephen Blundell
Experimenter: Professor Matja? Gomil?ek
Experimenter: Dr Thomas Hicken
Experimenter: Dr Benjamin Huddart
Local Contact: Dr Mark Telling
Experimenter: Dr Murray Wilson
Experimenter: Professor Jamie Manson
Experimenter: Dr Francis Pratt

DOI: 10.5286/ISIS.E.RB1820151

ISIS Experiment Number: RB1820151

Publisher: STFC ISIS Neutron and Muon Source

Data format: RAW/Nexus
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Data Citation

The recommended format for citing this dataset in a research publication is as:
[author], [date], [title], [publisher], [doi]

For Example:
Professor Tom Lancaster et al; (2019): The nature of excitations in a molecular Haldane system, STFC ISIS Neutron and Muon Source, https://doi.org/10.5286/ISIS.E.RB1820151

Data is released under the CC-BY-4.0 license.