Optical spectroscopy study of Ca_3(Ru_(0.91)Mn_(0.09))_2O_7 single crystal in high magnetic fields
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摘要
The magneto-optical spectrum, with magnetic fields up to 42 T, of double layered ruthenates Ca_3(Ru_(0.91)Mn_(0.09))_2O_7(CRMO) single crystal is studied. Both the temperature and magnetic field induced insulator-to-metal transitions(IMTs) are observed via magneto-optical properties of the crystal. The critical magnetic field(H//c) of IMT for CRMO is found to be as large as 35 T at 5 K. The fine structure of optical spectra identified the antiferromagnetic/ferro-orbital-ordering configurations of Ru 4d orbitals at low temperatures. Meanwhile, the configuration of orbital polarization of such double-layer CRMO single crystal is discussed. These results suggest that the orbital degree of freedom plays an important role in the field induced IMT of multi-orbital system.
The magneto-optical spectrum, with magnetic fields up to 42 T, of double layered ruthenates Ca_3(Ru_(0.91)Mn_(0.09))_2O_7(CRMO) single crystal is studied. Both the temperature and magnetic field induced insulator-to-metal transitions(IMTs) are observed via magneto-optical properties of the crystal. The critical magnetic field(H//c) of IMT for CRMO is found to be as large as 35 T at 5 K. The fine structure of optical spectra identified the antiferromagnetic/ferro-orbital-ordering configurations of Ru 4d orbitals at low temperatures. Meanwhile, the configuration of orbital polarization of such double-layer CRMO single crystal is discussed. These results suggest that the orbital degree of freedom plays an important role in the field induced IMT of multi-orbital system.
The magneto-optical spectrum, with magnetic fields up to 42 T, of double layered ruthenates Ca_3(Ru_(0.91)Mn_(0.09))_2O_7(CRMO) single crystal is studied. Both the temperature and magnetic field induced insulator-to-metal transitions(IMTs) are observed via magneto-optical properties of the crystal. The critical magnetic field(H//c) of IMT for CRMO is found to be as large as 35 T at 5 K. The fine structure of optical spectra identified the antiferromagnetic/ferro-orbital-ordering configurations of Ru 4d orbitals at low temperatures. Meanwhile, the configuration of orbital polarization of such double-layer CRMO single crystal is discussed. These results suggest that the orbital degree of freedom plays an important role in the field induced IMT of multi-orbital system.
引文
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[16]Yoshida Y,Ikeda SI,Matsuhata H,et al.Crystal and magnetic structure of Ca3Ru2O7.Phys Rev B 2005;72:054412.
[17]Bao W,Mao ZQ,Qu Z,et al.Spin valve effect and magnetoresistivity in single crystalline Ca3Ru2O7.Phys Rev Lett 2008;100:247203.
[18]Ke X,Peng J,Singh DJ,et al.Emergent electronic and magnetic state in Ca3Ru2O7induced by Ti doping.Phys Rev B 2011;84:201102.
[19]Peng J,Ke X,Wang GC,et al.From quasi-two-dimensional metal with ferromagnetic bilayers to Mott insulator with G-type antiferromagnetic order in Ca3(Ru1-xTix)2O7.Phys Rev B 2013;87:085125.
[20]Zhu M,Peng J,Tian W,et al.Tuning the competing phases of bilayer ruthenate Ca3Ru2O7via dilute Mn impurities and magnetic field.Phys Rev B2017;95:144426.
[21]Zhu M,Peng J,Zou T,et al.Colossal magnetoresistance in a Mott insulator via magnetic field-driven insulator-metal transition.Phys Rev Lett2016;116:216401.
[22]Zou T,Cao HB,Liu GQ,et al.Pressure-induced electronic and magnetic phase transitions in a Mott insulator:Ti-doped Ca3Ru2O7bilayer ruthenate.Phys Rev B 2016;94:041115.
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[26]Kagawa F,Ltou T,Miyagawa K,et al.Magnetic-field-induced Mott transition in a quasi-two-dimensional organic conductor.Phys Rev Lett 2004;93:127001.
[27]Dagotto E,Hotta T,Moreo A.Colossal magnetoresistant materials:the key role of phase separation.Phys Rep 2001;344:1-153.
[28]Cooper SL.Optical Spectroscopic Studies of Metal-Insulator Transitions in Perovskite-Related Oxides.In:Goodenough JB,editor.Localized to Itinerant Electronic Transition in Perovskite Oxides.Structure and Bonding.Springer,Berlin,Heidelberg;2001.
[29]Lee JS,Moon SJ,Yang BJ,et al.Pseudogap dependence of the optical conductivity spectra of Ca3Ru2O7:a possible contribution of the orbital flip excitation.Phys Rev Lett 2007;98:097403.
[30]Peng J,Hu J,Gu XM,et al.Normal and inverse bulk spin valve effects in singlecrystal ruthenates.Appl Phys Lett 2016;108:162402.
[31]Peng J,Gu MQ,Gu XM,et al.Mott transition controlled by lattice-orbital coupling in 3d-metal-doped double-layer ruthenates.Phys Rev B2017;96:205105.
[32]Kuwahara H,Tomioka Y,Asamitsu A,et al.A first-order phase-transition induced by a magnetic-field.Science 1995;270:961-3.
[33]Tokura Y.Critical features of colossal magnetoresistive manganites.Rep Prog Phys 2006;69:797-851.
[34]Jonker GH,Vansanten JH.Ferromagnetic compounds of manganese with perovskite structure.Physica 1950;16:337-49.
[35]Tokura Y,Nagaosa N.Orbital physics in transition-metal oxides.Science2000;288:462-8.
[2]Anderson PW.New approach to the theory of superexchange interactions.Phys Rev 1959;115:2-13.
[3]Hubbard J.Electron correlations in narrow energy bands.Proc R Soc London,Ser A 1963;276:238-57.
[4]Kanamori J.Electron correlation and ferromagnetism of transition metals.Prog Theor Phys 1963;30:275-89.
[5]Ruddlesden SN,Popper P.New compounds of the K2NIF4type.Acta Crystallogr1957;10:538-40.
[6]Ruddlesden SN,Popper P.The compound Sr3Ti2O7and its structure.Acta Crystallogr 1958;11:54-5.
[7]Nakatsuji S,Maeno Y.Quasi-two-dimensional Mott transition system Ca2-xSrxRuO4.Phys Rev Lett 2000;84:2666-9.
[8]Koga A,Kawakami N,Rice TM,et al.Orbital-selective Mott transitions in the degenerate Hubbard model.Phys Rev Lett 2004;92:216402.
[9]Lee JS,Lee YS,Noh TW,et al.Electron and orbital correlations in Ca2-xSrxRuO4probed by optical spectroscopy.Phys Rev Lett 2002;89:257402.
[10]Mizokawa T,Tjeng LH,Sawatzky GA,et al.Spin-orbit coupling in the Mott insulator Ca2RuO4.Phys Rev Lett 2001;87:077202.
[11]Jung JH,Fang Z,He JP,et al.Change of electronic structure in Ca2RuO4induced by orbital ordering.Phys Rev Lett 2003;91:056403.
[12]Hotta T,Dagotto E.Prediction of orbital ordering in single-layered ruthenates.Phys Rev Lett 2002;88:017201.
[13]Fang Z,Nagaosa N,Terakura K.Orbital-dependent phase control in Ca2-xSrxRuO4(0 x 0.5).Phys Rev B 2004;69:045116.
[14]Cao G,McCall S,Crow JE,et al.Observation of a metallic antiferromagnetic phase and metal to nonmetal transition in Ca3Ru2O7.Phys Rev Lett1997;78:1751-4.
[15]Yoshida Y,Nagai I,Ikeda SI,et al.Quasi-two-dimensional metallic ground state of Ca3Ru2O7.Phys Rev B 2004;69:220411.
[16]Yoshida Y,Ikeda SI,Matsuhata H,et al.Crystal and magnetic structure of Ca3Ru2O7.Phys Rev B 2005;72:054412.
[17]Bao W,Mao ZQ,Qu Z,et al.Spin valve effect and magnetoresistivity in single crystalline Ca3Ru2O7.Phys Rev Lett 2008;100:247203.
[18]Ke X,Peng J,Singh DJ,et al.Emergent electronic and magnetic state in Ca3Ru2O7induced by Ti doping.Phys Rev B 2011;84:201102.
[19]Peng J,Ke X,Wang GC,et al.From quasi-two-dimensional metal with ferromagnetic bilayers to Mott insulator with G-type antiferromagnetic order in Ca3(Ru1-xTix)2O7.Phys Rev B 2013;87:085125.
[20]Zhu M,Peng J,Tian W,et al.Tuning the competing phases of bilayer ruthenate Ca3Ru2O7via dilute Mn impurities and magnetic field.Phys Rev B2017;95:144426.
[21]Zhu M,Peng J,Zou T,et al.Colossal magnetoresistance in a Mott insulator via magnetic field-driven insulator-metal transition.Phys Rev Lett2016;116:216401.
[22]Zou T,Cao HB,Liu GQ,et al.Pressure-induced electronic and magnetic phase transitions in a Mott insulator:Ti-doped Ca3Ru2O7bilayer ruthenate.Phys Rev B 2016;94:041115.
[23]Laloux L,Georges A,Krauth W.Effect of a magnetic-field on mott-hubbard systems.Phys Rev B 1994;50:3092.
[24]Vollhardt D.Normal3He:an almost localized Fermi liquid.Rev Mod Phys1984;56:99-124.
[25]Georges A,Kotliar G,Krauth W.Dynamical mean-field theory of strongly correlated fermion systems and the limit of infinite dimensions.Rev Mod Phys1996;68:13-125.
[26]Kagawa F,Ltou T,Miyagawa K,et al.Magnetic-field-induced Mott transition in a quasi-two-dimensional organic conductor.Phys Rev Lett 2004;93:127001.
[27]Dagotto E,Hotta T,Moreo A.Colossal magnetoresistant materials:the key role of phase separation.Phys Rep 2001;344:1-153.
[28]Cooper SL.Optical Spectroscopic Studies of Metal-Insulator Transitions in Perovskite-Related Oxides.In:Goodenough JB,editor.Localized to Itinerant Electronic Transition in Perovskite Oxides.Structure and Bonding.Springer,Berlin,Heidelberg;2001.
[29]Lee JS,Moon SJ,Yang BJ,et al.Pseudogap dependence of the optical conductivity spectra of Ca3Ru2O7:a possible contribution of the orbital flip excitation.Phys Rev Lett 2007;98:097403.
[30]Peng J,Hu J,Gu XM,et al.Normal and inverse bulk spin valve effects in singlecrystal ruthenates.Appl Phys Lett 2016;108:162402.
[31]Peng J,Gu MQ,Gu XM,et al.Mott transition controlled by lattice-orbital coupling in 3d-metal-doped double-layer ruthenates.Phys Rev B2017;96:205105.
[32]Kuwahara H,Tomioka Y,Asamitsu A,et al.A first-order phase-transition induced by a magnetic-field.Science 1995;270:961-3.
[33]Tokura Y.Critical features of colossal magnetoresistive manganites.Rep Prog Phys 2006;69:797-851.
[34]Jonker GH,Vansanten JH.Ferromagnetic compounds of manganese with perovskite structure.Physica 1950;16:337-49.
[35]Tokura Y,Nagaosa N.Orbital physics in transition-metal oxides.Science2000;288:462-8.