title: Giant magnetic fluctuations at the critical endpoint in insulating HoMnO3.
abstract: Although abundant research has focused recently on the quantum criticality of itinerant magnets, critical phenomena of insulating magnets in the vicinity of critical endpoints (CEP's) have rarely been revealed. Here we observe an emergent CEP at 2.05 T and 2.2 K with a suppressed thermal conductivity and concomitant strong critical fluctuations evident via a divergent magnetic susceptibility (e.g., χ''(2.05  T,2.2  K)/χ''(3  T,2.2  K)≈23,500%, comparable to the critical opalescence in water) in the hexagonal insulating antiferromagnet HoMnO3.
authors.affiliation: Rutgers Center for Emergent Materials and Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, USA and Department of Physics and IPAP, Yonsei University, Seoul 120-749, Korea.
authors.forename: Y J
authors.initials: YJ
authors.lastname: Choi
authors.affiliation: Rutgers Center for Emergent Materials and Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, USA and Department of Physics and IPAP, Yonsei University, Seoul 120-749, Korea.
authors.forename: N
authors.initials: N
authors.lastname: Lee
authors.affiliation: Rutgers Center for Emergent Materials and Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, USA.
authors.forename: P A
authors.initials: PA
authors.lastname: Sharma
authors.affiliation: Rutgers Center for Emergent Materials and Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, USA.
authors.forename: S B
authors.initials: SB
authors.lastname: Kim
authors.affiliation: NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA.
authors.forename: O P
authors.initials: OP
authors.lastname: Vajk
authors.affiliation: NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA.
authors.forename: J W
authors.initials: JW
authors.lastname: Lynn
authors.affiliation: Rutgers Center for Emergent Materials and Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, USA.
authors.forename: Y S
authors.initials: YS
authors.lastname: Oh
authors.affiliation: Rutgers Center for Emergent Materials and Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, USA.
authors.forename: S-W
authors.initials: SW
authors.lastname: Cheong