Computational materials discovery of unconventional magnets
Location: CECAM-HQ-EPFL, Lausanne, Switzerland
Organisers
While magnetic materials have been in use for the past two thousand years, advances in the microscopic theoretical understanding of magnetism in the last century has led to a resurgence in exploring new magnets and several novel properties and magnetic phases have been discovered -- the anti-ferromagnetism in Mott insulators, colossal magneto-resistance, single molecule magnets are some of the examples. More recently, exotic magnetic phases hosting unconventional physics have been proposed and in some cases discovered, e.g, magnetic Skyrmions and non-collinear magnetic phases [1-2], quantum spin liquids [3] etc. These phases have promising technological applications in magnetic information coding and storage [4], and topological quantum computing [5], to name a few.
Material systems under active investigation for physical realization of these exotic phases include low-dimensional magnetic systems such as 1D (chains) and (quasi-) 2D materials owing to the prominence of quantum fluctuations [6], frustrated geometric lattice systems where magnetic frustration arises from competing exchange interactions [3], magnetic anisotropy and bond dependent exchange interactions due to strong spin-orbit interactions as in the Kitaev honeycomb model [7] and magnetic materials with topologically protected phases [8].
Very recently, the first example of magnetic order in a 2D material was reported experimentally [9]. This is a truly remarkable result, because the Mermin-Wagner theorem forbids spontaneous symmetry breaking in 2D and the magnetic order has to originate solely from magnetic anisotropy. The mechanism underlying magnetic order in 2D is thus fundamentally different than in 3D and the theory of magnetism in 2D is still in its infancy. In particular, while easy-axis magnetism may give rise to conventional long range order, easy-plane materials may exhibit Kosterlitz-Thouless physics with critical behavior within a large range of temperatures. Furthermore, magnetic order originating from the presence of defects in 2D materials such as graphene [10,11] and transition metal dichalcogenides [12] remains a popular subject.
The field of unconventional magnetism that deals with understanding, prediction and realization of exotic quantum magnetic phases in materials, is highly multidisciplinary involving condensed matter physicists, solid-state chemists and material scientists from both theory and experimental domains. Nevertheless, the pace of materials discovery for realizing exotic magnetic phases is rather slow. While, computational discovery of materials with non-magnetic properties has seen a great success, theoretical prediction of magnetic properties remains uncertain. To some extent, this is due to the challenges associated with the proper description of strong electronic correlations inherent is these materials.
The proposed workshop aims to bring together researchers both from theory and experiments working on different aspects of the field to present the latest advancements and to discuss the efforts required to expedite the discovery of new unconventional magnetic materials. The workshop facilitates interaction among specialists working with different novel magnets, using different computational methods resulting in the interface of theory and experiment.
The key topics that will be focused on in this workshop are:
-- Quantum spin liquid candidates
-- Materials hosting Skyrmions and non-collinear magnetic phases
-- Two-dimensional magnetic materials
-- Magnetic materials hosting topologically protected phases
-- Magnetism in nanomaterials and defect-induced magnetism
-- High-throughput computational search and design of materials
References
Thomas Olsen (Technical University of Denmark) - Organiser
Germany
Vamshi Mohan Katukuri (Max Planck Institute for Solid State Research) - Organiser
Switzerland
Oleg Yazyev (Ecole Polytechnique Fédérale de Lausanne (EPFL)) - Organiser