18 July 2016

Crystallization of spin superlattices using pressure and magnetic field

Pressure-driven tuning of bosonic crystal states in layered model magnet SrCu2(BO3)2 Pressure-driven tuning of bosonic crystal states in layered model magnet SrCu2(BO3)2

Discovery of a new kind of electron spin superstructure in crystals opens the tantalizing prospect of finding other emergent exotic phases.

First, some background

In quantum mechanics, one of the ways that particles are classified is through a property known as spin (imagine a spinning basketball): fermions have half-integer-spins, for example, and bosons have integer-spins. Under the right conditions, bosonic particles can either condense into a single, collective state of identical particles or form special crystalline superstructure patterns. They are referred to as superstructure patterns since they exist on top of the existing crystal structure formed by the atoms that make up the material.

What did scientists discover?

Scientists working at the National MagLab's DC Field Facility subjected a model magnetic material — SrCu2(BO3)2 — to a combination of extreme environments: very low temperatures, high magnetic fields and high pressures. Under these conditions, the material revealed a complex interplay of competing quantum interactions that resulted in a sequence of bosonic superstructure patterns called superlattices. Scientists were able to manipulate these patterns by changing the environments of the material.

Why is this important?

When interacting collectively, quantum particles can form exotic liquids and solids with unusual properties, such as flowing without friction (superfluid) or having their ordered, frozen state disrupted. Discovery of these new bosonic superstructure crystals opens the tantalizing prospect of finding other emergent exotic phases of matter, including the so-called supersolid phase, a hybrid state where a solid crystal appears to move like a superfluid. Since the world we experience emerges from quantum mechanical interactions the exploration of these phenomena is key to understanding how our world works.

Who did the research?

S. Haravifard1, D. Graf2, A.E. Feiguin3, C.D. Batista4, J.C. Lang5, D.M. Silevitch6, G. Srajer5, B.D. Gaulin7, H.A. Dabkowska7, T.F. Rosenbaum6

1Duke University; 2MagLab and Florida State University; 3Northeastern University; 4University of Tennessee; 5Argonne National Lab; 6California Institute of Technology; 7McMaster University

Why did they need the MagLab?

THE TOOLS THEY USED

This research was conducted in the 35 T Resistive Magnet (cell 12) at the MagLab's DC Field Facility.

Widely known for its world-record magnetic fields, the National MagLab also offers scientists cutting edge tools and techniques, such as high-pressure cells and environments at temperatures near absolute zero, that allow scientists to subject materials to unique combinations of extreme conditions that can reveal hidden physical properties. The combination of high pressure, high fields and cryogenic temperatures uniquely available at the MagLab enabled the discovery of the formation of new types of bosonic crystal patterns.

Details for scientists

Funding

This research was funded by the following grants: G.S. Boebinger (NSF DMR-1157490), S.H. (Duke Endowment); D.G. (NSF DMR-1157490, DOE NNSA DE-NA0001979); S.H., D.M.S., T.F.R. (NSF DMR-1206519); S.H., J.C.L, G.S. (DOE NEAC02-06CH11357); A.E.F.(NSF DMR- 1339564)


For more information, contact Tim Murphy.

Details

  • Research Area: Magnetism and Magnetic Materials
  • Research Initiatives: Materials
  • Facility / Program: DC Field
  • Year: 2016
Last modified on 19 July 2016