title: Dramatic pressure-driven enhancement of bulk skyrmion stability.
abstract: The recent discovery of magnetic skyrmion lattices initiated a surge of interest in the scientific community. Several novel phenomena have been shown to emerge from the interaction of conducting electrons with the skyrmion lattice, such as a topological Hall-effect and a spin-transfer torque at ultra-low current densities. In the insulating compound Cu2OSeO3, magneto-electric coupling enables control of the skyrmion lattice via electric fields, promising a dissipation-less route towards novel spintronic devices. One of the outstanding fundamental issues is related to the thermodynamic stability of the skyrmion lattice. To date, the skyrmion lattice in bulk materials has been found only in a narrow temperature region just below the order-disorder transition. If this narrow stability is unavoidable, it would severely limit applications. Here we present the discovery that applying just moderate pressure on Cu2OSeO3 substantially increases the absolute size of the skyrmion pocket. This insight demonstrates directly that tuning the electronic structure can lead to a significant enhancement of the skyrmion lattice stability. We interpret the discovery by extending the previously employed Ginzburg-Landau approach and conclude that change in the anisotropy is the main driver for control of the size of the skyrmion pocket.
authors.affiliation: Institute of Physics, Bijenička 46, HR-10 000, Zagreb, Croatia.
authors.forename: I
authors.initials: I
authors.lastname: Levatić
authors.affiliation: Institute of Physics, Bijenička 46, HR-10 000, Zagreb, Croatia.|Institute of Solid State Physics, TU Wien, A-1040 Vienna, Austria.
authors.forename: P
authors.initials: P
authors.lastname: Popčević
authors.affiliation: Institute of Physics, Bijenička 46, HR-10 000, Zagreb, Croatia.
authors.forename: V
authors.initials: V
authors.lastname: Šurija
authors.affiliation: Laboratory for Quantum Magnetism, Institute of Physics, EPFL, CH-1015 Lausanne, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Kruchkov
authors.affiliation: Crystal Growth Facility, Institute of Physics, EPFL, CH-1015 Lausanne, Switzerland.
authors.forename: H
authors.initials: H
authors.lastname: Berger
authors.affiliation: Crystal Growth Facility, Institute of Physics, EPFL, CH-1015 Lausanne, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Magrez
authors.affiliation: Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institut, CH-5232 Villigen, Switzerland.
authors.forename: J S
authors.initials: JS
authors.lastname: White
authors.affiliation: Laboratory for Quantum Magnetism, Institute of Physics, EPFL, CH-1015 Lausanne, Switzerland.
authors.forename: H M
authors.initials: HM
authors.lastname: Rønnow
authors.affiliation: Institute of Physics, Bijenička 46, HR-10 000, Zagreb, Croatia.|Laboratory for Quantum Magnetism, Institute of Physics, EPFL, CH-1015 Lausanne, Switzerland.
authors.forename: I
authors.initials: I
authors.lastname: Živković