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Magnetic correlations and quantum criticality in the insulating antiferromagnetic, insulating spin liquid, renormalized Fermi liquid, and metallic antiferromagnetic phases of the Mott system V_2O_3

Bao, Wei and Broholm, C. and Aeppli, G. and Carter, S. A. and Dai, P. and Rosenbaum, T. F. and Honig, J. M. and Metcalf, P. and Trevino, S. F. (1998) Magnetic correlations and quantum criticality in the insulating antiferromagnetic, insulating spin liquid, renormalized Fermi liquid, and metallic antiferromagnetic phases of the Mott system V_2O_3. Physical Review B, 58 (19). pp. 12727-12748. ISSN 0163-1829. https://resolver.caltech.edu/CaltechAUTHORS:20140707-163032301

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Abstract

Magnetic correlations in all four phases of pure and doped vanadium sesquioxide (V_2O_3) have been examined by magnetic thermal-neutron scattering. Specifically, we have studied the antiferromagnetic and paramagnetic phases of metallic V_(2-y)O_3, the antiferromagnetic insulating and paramagnetic metallic phases of stoichiometric V_2O_3, and the antiferromagnetic and paramagnetic phases of insulating V_(1.944)Cr_(0.056)O_3. While the antiferromagnetic insulator can be accounted for by a localized Heisenberg spin model, the long-range order in the antiferromagnetic metal is an incommensurate spin-density wave, resulting from a Fermi surface nesting instability. Spin dynamics in the strongly correlated metal are dominated by spin fluctuations with a "single lobe'' spectrum in the Stoner electron-hole continuum. Furthermore, our results in metallic V_2O_3 represent an unprecedentedly complete characterization of the spin fluctuations near a metallic quantum critical point, and provide quantitative support for the self-consistent renormalization theory for itinerant antiferromagnets in the small moment limit. Dynamic magnetic correlations for ħω<k_BT in the paramagnetic insulator carry substantial magnetic spectral weight. However, they are extremely short-ranged, extending only to the nearest neighbors. The phase transition to the antiferromagnetic insulator, from the paramagnetic metal and the paramagnetic insulator, introduces a sudden switching of magnetic correlations to a different spatial periodicity which indicates a sudden change in the underlying spin Hamiltonian. To describe this phase transition and also the unusual short-range order in the paramagnetic state, it seems necessary to take into account the orbital degrees of freedom associated with the degenerate d orbitals at the Fermi level in V_2O_3.


Item Type:Article
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URLURL TypeDescription
http://dx.doi.org/10.1103/PhysRevB.58.12727DOIArticle
http://journals.aps.org/prb/abstract/10.1103/PhysRevB.58.12727PublisherArticle
Alternate Title:Magnetic correlations and quantum criticality in the insulating antiferromagnetic, insulating spin liquid, renormalized Fermi liquid, and metallic antiferromagnetic phases of the Mott system V2O3
Additional Information:© 1998 The American Physical Society. Received 28 April 1998. We gratefully acknowledge discussions and communications with T. M. Rice, S. K. Sinha, Q. M. Si, G. Sawatzky, L. F. Mattheiss, G. Kotliar, C. Castellani, A. Fujimori, M. Takigawa, A. J. Millis, R. J. Birgeneau, G. Shirane, S. M. Shapiro, C. Varma, and T. Moriya. W. B. would like to thank R. W. Erwin, J. W. Lynn, D. A. Neumann, and J. J. Rush for their hospitality during experiments at NIST. W.B. and C.B. thank C. L. Chien and Q. Xiao for use of their laboratory for sample preparations. The work at JHU was supported by the NSF through Grant No. DMR-9453362, at BNL by DOE under Contract No. DE-AC02-98CH10886, at ORNL by DOE under Contract No. DE-AC05-96OR22464, at Purdue by MISCON Grant No. DE-FG02-90ER45427, and at the University of Chicago by the NSF through Grant No. DMR-9507873.
Funders:
Funding AgencyGrant Number
NSFDMR-9453362
Department of Energy (DOE)DE-AC02-98CH10886
Department of Energy (DOE)DE-AC05-96OR22464
Department of Energy (DOE)DE-FG02-90ER45427
NSFDMR-9507873
Issue or Number:19
Record Number:CaltechAUTHORS:20140707-163032301
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20140707-163032301
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:46978
Collection:CaltechAUTHORS
Deposited By: George Porter
Deposited On:09 Jul 2014 20:54
Last Modified:03 Oct 2019 06:48

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