Publications de Peter Babkevich

Cavity-magnon-polariton spectroscopy of strongly hybridized electro-nuclear spin excitations in LiHoF4

Richard Gaal, Henrik Moodysson Rønnow, Ivica Zivkovic, Peter Babkevich

We first present a formalism that incorporates the input-output formalism and the linear response theory to employ cavity-magnon-polariton coupling as a spectroscopic tool for investigating strongly hybridized electro-nuclear spin excitations. A microscopi ...

Nature Research2024

Structure, Spin Correlations, and Magnetism of the S=1/2 Square-Lattice Antiferromagnet Sr2CuTe1-xWxO6 (0 ≤ x ≤ 1)

Henrik Moodysson Rønnow, Peter Babkevich, Sami Juhani Vasala, Ellen Fogh

Quantum spin liquids are highly entangled magnetic states with exotic properties. The S = 1/2 square-lattice Heisenberg model is one of the foundational models in frustrated magnetism with a predicted, but never observed, quantum spin liquid state. Isostru ...

Amer Chemical Soc2023

Randomness and frustration in a S = (1/)(2) square-lattice Heisenberg antiferromagnet

Bruce Normand, Henrik Moodysson Rønnow, Peter Babkevich, Ellen Fogh

We explore the interplay between randomness and magnetic frustration in the series of S = 12 Heisenberg square-lattice compounds Sr2CuTe1???xWxO6. Substituting W for Te alters the magnetic interactions dramatically, from strongly nearest-neighbor to next-n ...

2022

Spin dynamics in the square-lattice cupola system Ba(TiO)Cu-4(PO4)(4)

Bruce Normand, Henrik Moodysson Rønnow, Luc Testa, Virgile Yves Favre, Peter Babkevich

We report high-resolution single-crystal inelastic neutron scattering measurements on the spin-1/2 antiferromagnet Ba(TiO)Cu-4(PO4)(4). This material is formed from layers of four-site "cupola" structures, oriented alternately upwards and downwards, which ...

AMER PHYSICAL SOC2022

Magnetic Field Induced Quantum Spin Liquid in the Two Coupled Trillium Lattices of K2Ni2(SO4)(3)

Arnaud Magrez, Henrik Moodysson Rønnow, Ivica Zivkovic, Luc Testa, Virgile Yves Favre, Peter Babkevich, Nagabhushan Ganesh Hegde

Quantum spin liquids are exotic states of matter that form when strongly frustrated magnetic interactions induce a highly entangled quantum paramagnet far below the energy scale of the magnetic interactions. Three-dimensional cases are especially challengi ...

AMER PHYSICAL SOC2021

Exchange Interactions Mediated by Nonmagnetic Cations in Double Perovskites

Oleg Yazyev, Henrik Moodysson Rønnow, Peter Babkevich, Vamshi Mohan Katukuri, Sami Juhani Vasala

Establishing the physical mechanism governing exchange interactions is fundamental for exploring exotic phases such as quantum spin liquids in real materials. In this Letter, we address exchange interactions in Sr2CuTexW1-xO6, a series of double perovskite ...

AMER PHYSICAL SOC2020

Singlet state formation and its impact on the magnetic structure in the tetramer system SeCuO3

Helmuth Berger, Arnaud Magrez, Krunoslav Prsa, Henrik Moodysson Rønnow, Ivica Zivkovic, Peter Babkevich

We present an experimental investigation of the magnetic structure in a tetramer system SeCuO3 using neutron powder-diffraction and nuclear resonance techniques. We establish a commensurate antiferromagnetic ordering with a propagation vector k = (0, 0, 1) ...

2018

24-spin clusters in the mineral boleite KPb26Ag9Cu24Cl62(OH)(48)

Henrik Moodysson Rønnow, Goran Nilsen, Ivica Zivkovic, Peter Babkevich, Ursula Bengaard Hansen, Nicola Casati

2018

A-cation control of magnetoelectric quadrupole order in A(TiO)Cu-4(PO4)(4) (A = Ba, Sr, and Pb)

Henrik Moodysson Rønnow, Peter Babkevich

2018

Note: Commercial SQUID magnetometer-compatible NMR probe and its application for studying a quantum magnet

Helmuth Berger, Henrik Moodysson Rønnow, Ivica Zivkovic, Tarek Axel Vennemann, Peter Babkevich, Lin Yang

2018

Electronic and magnetic excitations in the half-stuffed Cu-O planes of Ba2Cu3O4Cl2 measured by resonant inelastic x-ray scattering

Marco Grioni, Bruce Normand, Henrik Moodysson Rønnow, Peter Babkevich, Sara Fatale, Noore Elahi Shaik, Claudia Giuseppina Fatuzzo, Thorsten Schmitt

We use resonant inelastic x-ray scattering (RIXS) at the Cu L3 edge to measure the charge and spin excitations in the “half-stuffed” Cu-O planes of the cuprate antiferromagnet Ba2Cu3O4Cl2. The RIXS line shape reveals distinct contributions to the dd excita ...

2017

J1−J2 square-lattice Heisenberg antiferromagnets with 4d1 spins: AMoOPO4Cl (A=K,Rb)

Henrik Moodysson Rønnow, Peter Babkevich

Magnetic properties of AMoOPO4Cl (A=K,Rb) with Mo5+ ions in the 4d1 electronic configuration are investigated by magnetization, heat capacity, and nuclear magnetic resonance (NMR) measurements on single crystals, combined with powder neutron diffraction ex ...

2017

J1-J2 square lattice antiferromagnetism in the orbitally quenched insulator MoOPO4

Helmuth Berger, László Forró, Arnaud Magrez, Oleg Yazyev, Bálint Náfrádi, Henrik Moodysson Rønnow, Ivica Zivkovic, Peter Babkevich, Lin Yang, Noore Elahi Shaik

We report magnetic and thermodynamic properties of a 4d1 (Mo5+) magnetic insulator MoOPO4 single crystal, which realizes a J1−J2 Heisenberg spin-1/2 model on a stacked square lattice. The specific-heat measurements show a magnetic transition at 16 K which ...

Amer Physical Soc2017

Magnetic structure of Ba(TiO)Cu4(PO4)4 probed using spherical neutron polarimetry

Henrik Moodysson Rønnow, Luc Testa, Peter Babkevich, Gregory Scott Tucker

The antiferromagnetic compound Ba(TiO)Cu4(PO4)4 contains square cupola of corner-sharing CuO4 plaquettes, which were proposed to form effective quadrupolar order. To identify the magnetic structure, we have performed spherical neutron polarimetry measureme ...

2017

Magnetic excitations from the two-dimensional interpenetrating Cu framework in Ba2Cu3O4Cl2

Henrik Moodysson Rønnow, Diane Virginie Marie Lançon, Mechthild Enderle, Peter Babkevich, Noore Elahi Shaik

We report detailed neutron scattering studies on Ba2Cu3O4Cl2. The compound consists of two interpenetrating sublattices of Cu, labeled as Cu-A and Cu-B, each of which forms a square-lattice Heisenberg antiferromagnet. The two sublattices order at different ...

Amer Physical Soc2017

Magnetic quadrupolar order in the chiral square cupola compound BaTiOCu4(PO4)4

Henrik Moodysson Rønnow, Luc Testa, Peter Babkevich, Gregory Scott Tucker

We report neutron diffraction studies of the magnetic structure in BaTiOCu4(PO4)4 , which is a newly discovered magneticinsulator crystallizing in a tetragonal chiral crystal structure with P4212 space group [1]. The crystal structure ischaracterized by an ...

2017

Spin excitations in the skyrmion host Cu2OSeO3

Arnaud Magrez, Henrik Moodysson Rønnow, Ivica Zivkovic, Jonathan White, Peter Babkevich, Ping Huang, Felix Groitl, Gregory Scott Tucker

We have used inelastic neutron scattering to measure the magnetic excitation spectrum along the high-symmetry directions of the first Brillouin zone of the magnetic skyrmion hosting compound Cu2OSeO3. The majority of our scattering data are consistent with ...

Amer Physical Soc2016

Dimensional Reduction in Quantum Dipolar Antiferromagnets

Henrik Moodysson Rønnow, Martin Mansson, Ivan Kovacevic, Peter Babkevich

We report ac susceptibility, specific heat, and neutron scattering measurements on a dipolar-coupled antiferromagnet LiYbF4. For the thermal transition, the order-parameter critical exponent is found to be 0.20(1) and the specific-heat critical exponent -0 ...

2016

Magnetic Excitations and Electronic Interactions in Sr2CuTeO6: A Spin-1/2 Square Lattice Heisenberg Antiferromagnet

Oleg Yazyev, Henrik Moodysson Rønnow, Peter Babkevich, Vamshi Mohan Katukuri

Sr2CuTeO6 presents an opportunity for exploring low-dimensional magnetism on a square lattice of S = 1/2 Cu2+ ions. We employ ab initio multireference configuration interaction calculations to unravel the Cu2+ electronic structure and to evaluate exchange ...

2016

Magnetodielectric detection of magnetic quadrupole order in Ba(TiO)Cu4(PO4)4 with Cu4O12 square cupolas

Henrik Moodysson Rønnow, Peter Babkevich, Julia Martius, Gregory Scott Tucker

In vortex-like spin arrangements, multiple spins can combine into emergent multipole moments. Such multipole moments have broken space-inversion and time-reversal symmetries, and can therefore exhibit linear magnetoelectric (ME) activity. Three types of su ...

Nature Research2016