gs bNXtXg[g¥«Ì Ba3CuSb2O9 ÌXsÆO¹ÌÖáÑTåãåwåw@îbHw¤Èv |8531 åã{LsÒR¬ 1_3§560_XstÌIUé¢ð¦· Ba3CuSb2O9 ÍCÅßÌ¤ÉæÁÄXsÆdqO¹Ì 2 ÂÌ©RxªÊqÍwIÉ¬´Á½C¨¿ÌVµ¢óÔðÀ»µÄ¢éÆñÄ³êÄ¢éBäXÍ±Ì¨¿Ì 3d O¹ÌóÔzuÉ©çêéZ£âO¹zuÌÔÖðCX üUUªèðSÆµ½è@ÅªèµCO¹©RxÌ·xÏ»ª¥«Ée¿³êÄ¢éð©oµ½BÊíÍ¥CIÈÝìpÍO¹©RxÌÔÌÝìpæèã¢½ßÉ¥«ªO¹
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Fig. 1(Color online) (a) Structure of Ba3CuSb2O9. Half of (Cu,Sb)O6 octahedra are CuO6, and the rest are SbO6, i.e., which
are disordered. (b) c­axis view of the crystal structure. Short
range honeycomb structure is reported in ref. 6). (c) Strain
eld induced by a JT­distorted CuO6 octahedron within thec­plane highlighted in panel (a). Reproduced with permis­sion from 9). Copyright 2013 Nature Publishing Group.

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50 K OãÅêÌ Cu2{ ÌdqªüÍÌ Cu2{ ÌdqÆyO¹óÔðÏª·éªßçê½B»±ÅäXÍO¹ÌAðìèC ñ¥«ÌX sVO bgóÔ ÉÈéBZ £ Ö ðÏ ª·é ½ß ÉC X ü U U ðp µCu2{ Í 3d O¹Édqð 9 Â¿CXs©Rx¾¯Å

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(C) 2014 The Japanese Society for Synchrotron Radiation ResearchgsbNX ¡ tXg[g¥«Ì Ba3CuSb2O9 ÌXsÆO¹ÌÖÆCO¹ÌÖÉÏ»ª¶¶é·xÆªêv·élqªÏO¹Ì^®ªüÍÌiqðcÜ¹éÉ«é¾¯x¯êª³êC±Ì¨¿ÅO¹ÆXsªÖAµ½óµªÀ»µÎCcñ¾ªÊÌÍiqSÌðcÜ¹C»ÌÀiÎÌ«Ä¢é±ÆðÀ±IÉmFÅ«½9)BÈºCO¹Z£ðö·B»Ìæ¤È\¢Ï`ÍCBragg ½ËüÓÉLªÁÖÌÏªÌ´ÆCÀÛÌÀ±ÊðÐî·éB½UUÆµÄÏª³êéBÜ¸ÍcÝÌÈ¢iqÌÉCÇ§µ½ JT cÝðÂªÊÌðßñ¾óµðl2. »µÈ¢O¹ÌÏª@\Huang U

¦æ¤BFig. 1(c)É¦·æ¤ÉCcñ¾ªÊÌðSÉÙûIÈÐ¸Ýª»iqÉ¶¶éB±Ìæ¤Èg_×üªÊÌzÊµ½JÚà®ÌêCO¹©RxÍ Jahn­ÓÉ¶¶écÝê©çÌX üUhÍ Huang UÆµÄTeller øÊiJT øÊjÉæÁÄªÊÌðcÜ¹éBÁÉmçêÄ¨è10) CA±Ìßðp¢Ä­xªzðvZÅMn â Cu Ìæ¤É 3z 2 _r 2 â x 2 _y 2 ÌO¹ÌèLóÔªÏ« é B Huang U  ­ x Í  S Ì Bragg ½ Ë ­ x É ä á»·éêCå«ÈªÊÌÌÏ`ªN±éBBa3CuSb2O9µC®aûüÉÍtiq_©çÌ£ q Ì©æÉ½äáµÌêCEXAFS ÉæÁÄ 4 ÂÌ Cu_O £ª2.03 ÅC2½­xªzð¦·Bå«ÈÁ¥ÍC»Ì­xªzªÉßÄÂÌ Cu_O £ª2.26 Å ÉÈéªñ³êÄ¨è6) C­¢Ùû«ðÂ±ÆÅ

x 2 _y 2 iÆ­­ÖWµÄ¢éBªÊÌªSÌÉc£·éæ¤ÈÏ`é¢Í y 2_z 2 © z 2 _x 2 jÉz[ªüÁÄ¢é

éB±ÌÙû«ÍcÝÌ[hªí©éB±Ì Cu_O £Í300 K Æ10 K ÅÙÆñÇ·ÌêiSà®CIÌ¿ªÙÈéêÉæ­©çêxÏ»ª³­CÂXÌTCgÅ©éÆº·ÈºÅ Cu ÌOéjÆC¡ñÌæ¤È JT cÝð¼èµÄvZµ½ihk0j¹óÔÍÃI\±±ÅÍªÊÌðcÜ¹éÌÉ[ªÈÊih, k2.5öxjÌU­xªzð Fig. 2(a), (b)É¦ÔCêÂÌO¹Éz[ª¯ÜÁÄ¢éðÓ¡·é\Éµ½B[hÌá¢Éæé­xªzÌá¢Í¾ç©Å éB©¦éBO¹ÌÔÉóÔÖªêûCP» X ü\¢ðÍÅÍº·Å±Ì¨¿ÍZûéÆÇ¤ÈéÅë¤©BHu­ang Uð¶ÞcÝêÌ´qÏÊªC¡Ì CuO6 ªÊÌè6)CCuO6 ªÊÌÍOñÎÌðÂ½ßÉ JT cÝNöÌcÝêðPÉ«µí¹éÅßÅ«éÆ¼èðÂ±ÆªÅ«È¢Bê© EXAFS ÌÊÆµµÄ·éBOûüÇ¿çÉªÊÌªLÑÄ¢é©
iO¹©Rxj»Å©¦éªC3 íÌûüÉ JT cÝðN±µ½ªÊÌª·£ð½¸ÉzuµÄ»ð`¬µÄ¢éÆ¼è·éÅ EXAFS ÌÊÆ®«ðæé±ÆªÅ«éBg¬ð÷­É¸çµ½ Ba3Cu1_dSb2{dO9 ðìéÆ200 K tßÅZû»©çÎû»É]Ú·éêûCd ð¬³­·éÆá·ÜÅZû»ðÛÂ¿ª¾çêé6)B±ÌÎû»ÖÌ]ÚÍC¯¶ûüÉ JT cÝª®ñ·éC¢íÎ­O¹]ÚÅ

éÆ¢¤©ûªÅ«éBïÌIÉÍCFig. 1(c)É¦µ½ c ÊàÌiCu, Sb)O6 ªÊÌª·×Ä¡ûüÉLÑ
ÄCa{ b, a| b, c Ì 3 Âðî{ÀixNgÆ·éÎû»ªÀ»·éCÆ¢¤]ÚÅéB»ÀÌ»ÅÍCc ²üèÉ}120ñ]µ½ûüÉªÊÌÌÏ`ªü¢½hCª¬ÝµÄC]ÚÆÆàÉ Bragg ½Ëªªô·éB±Ì]Ú·x©çCO¹ÔÌÝìpÍ200 K öxÌGlM[XP[ÅéÆ©ÏàçêéBÊ¢ÌÍá·ÜÅZû»ðÛÂ¿ÅéB»Ìæ¤È¿ÅÍC200 K öxÌGlM[XP[ÌO¹ÔÌÝìpªéÉàÖíç¸C1 K ÈºÅàO¹ðN±³È¢B±êÍCOpiqÌCWO½­¥«Ìªá·ÜÅ»Å«È¢ÌÆ½óµÅéæ¤É©¦éB½¾µCO¹ÔÌÝìpª½­IÈÌ©­IÈÌ©Í©¾ÅÍÈ¢B­IÈÝìpÅéÈçÎ200 K½èÅÎû»É]ÚµÈ¢RªÈ¢BêûC½­IÈÝìpÅéÈçÎCg¬ª­µ¸ê½¿ª200 K tßÅÎû»É]Ú·éRª³¢BO¹ÔÌÝìpªÇÌæ¤ÉÈÁÄ¢éÌ©ðmé½ßÉCO¹ÔÌÔÉóÔÖªÇ¤ÈÁÄ¢é©ðÏ
ª·é±ÆªKvÅéBFig. 2 (Color online) (a) Calculated Huang scattering intensity
distribution for isotropically expanded point defects in ahexagonal lattice. (b) That for elongated octahedra in ahexagonal lattice. The blue rectangle highlights the region wemeasured. (c) Obaserved diuse intensity distribution
around 220 Bragg reection of Ba3CuSb2O9 at 290 K. (d)that at 4 K. Reproduced with permission from 9). Copyright2013 Nature Publishing Group.

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@ðæé±ÆÉµ½BOÒÌû@ÅÍCvZãÌ­xª[ÌèL¦C q ÍUxNg Q Ìtiq_©çÌ¸êCÉÈéi¡ñÌêCtiq_ðÊé D ûüÌüãjt a(q) Í´_É éO¹ a ÉNö·écÝÌt[GÏ·CÌüÓÅvë·ðñíÉgåµÄ©ÄµÜ¤±ÆCyÑt aÞ(q) Í»Ì¡f¤ðCN Í¿Ì CuO6 ªÊÌÌÅÙÈéíÞÌO¹ÌÔÌóÔÖÉÎ·éW Q ÉtaÞ(q)QéBm ÉÖ·éaÍ¿SÌÉí½ÁÄæèCO¹ÌÉtb ( q) Ía| Q Éta ( q)|2 ÆÙÈé½ßC»êÙÇmèIÈñÌÖÖqra( 0)rb(r)rÌt[GÏ·ð^¦éB³O¹ÌóÔÖÌîñª¾çêéí¯ÅÍÈ¢±ÆÌ 2ÖÌêÉÍqra ( 0)rb (r)rª ab ©Â rm  0 ÌÌÂÌRÉæéBÝ 1C»êÈOÅ 0 ÆÈé½ßCmcnÌªª dab ÆÈFig. 3(a), (b)É290 K Æ 4 K Åªèµ½ I(Q)Éq2 ð}¦èCÊÆµÄ Iåa| Q Ét a ( q)|2 ÉÈéBq ª¬³¢êµ ½ B ± ± Å C v Z É K v È e « è  Í SPring­8

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168  úËõ May 2014 Vol.27 No.3

gsbNX ¡ tXg[g¥«Ì Ba3CuSb2O9 ÌXsÆO¹ÌÖFig. 3(Color online) Experimentally observed intensity around 220 Bragg reection multiplied by q2 at (a) 290 K and(b) 4 K. Calculated one with noncorrelated orbitals is presented in panel (c). Panels (d) and (e) show the calcu­
lated IÉq2 map for ferro orbital order cluster and antiferro orbital order cluster, respectively. Reproduced withpermission from 9). Copyright 2013 Nature Publishing Group.

Fig. 4(Color online) (a) Line proles of IÉq2 along the dashed line in Fig. 3(a) measured at several temperatures. (b)Temperature variation of the peak area and width of IÉq2 profole. Top panel shows the magnetic succeptibility13).
Both orbital and spin degrees of freedom show anomaly at 60 K, which is comparable temperature with the energy
scale of the magnetic interaction. Reproduced with permission from 9). Copyright 2013 Nature PublishingGroup.

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L. Balents: Nature 464, 199_208 (2010).
H. Kawamura: J. Phys.: Condens. Matter 10, 4707_4754(1998).
H. Morita, S. Watanabe and M. Imada: J. Phys. Soc. Jpn. 71,
2109_2112 (2002).
S. Nakatsuji, Y. Nambu, H. Tonomura, O. Sakai, S. Jonas,C. Broholm, H. Tsunetsugu, Y. Qiu and Y. Maeno: Science309, 1697 (2005).
V. P. K äohl: Z. Anorg. Allg. Chem. 442, 280 (1978).
S. Nakatsuji, K. Kuga, K. Kimura, R. Satake, N. Katayama,
E. Nishibori, H. Sawa, R. Ishii, M. Hagiwara, F. Bridges, T.
U. Ito, W.Higemoto, Y. Karaki, M. Halim, A. A. Nugroho, J.
A. Rodriguez­Rivera, M. A. Green and C. Broholm: Science336, 559 (2012).
B. Nienhuis, H. J. Hilhorst and H. W. J. Bl äote: J. Phys. A:Math. Gen. 17, 3359 (1984).
J. Nasu and S. Ishihara: Phys. Rev. B 88, 094408 (2013).
Y. Ishiguro, K. Kimura, S. Nakatsuji, S. Tsutsui, A. Q. R.
Baron, T. Kimura and Y. Wakabayashi: Nature Commun. 4,2022 (2013).
P. H. Dederichs: J. Phys. F: Met. Phys. 3, 471_496 (1973).
S. Shimomura, N. Wakabayashi, H. Kuwahara and Y.
Tokura: Phys. Rev. Lett. 83, 43894392 (1999).
L. Vasiliu­Doloc, S. Rosenkranz, R. Osborn, S. K. Sinha, J.
W. Lynn, J. Mesot, O. H. Seeck, G. Preosti, A. J. Fedro andJ. F. Mitchell: Phys. Rev. Lett. 83, 4393_4396 (1999) 4393.
J. A. Quilliam, F. Bert, E. Kermarrec, C. Payen, C. Guillot­
Deudon, P. Bonville, C. Baines, H. Luetkens and P. Men­dels: Phys. Rev. Lett. 109, 117203_1_5 (2012).
H. D. Zhou, E. S. Choi, G. Li, L. Balicas, C. R. Wiebe, Y.
Qiu, J. R. D. Copley and J. S. Gardner: Phys. Rev. Lett. 106,147204_
1_4 (2011).

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gsbNX ¡ tXg[g¥«Ì Ba3CuSb2O9 ÌXsÆO¹ÌÖSpin­orbital correlation in frustrated magnet
Ba3CuSb2O9
Yusuke WAKABAYASHI
Abstract

Division of Materials Physics, Graduate School of Engineering Science,
Osaka University, Toyonaka 560_8531, Japan

Based on recent experimental and theoretical studies, the spin liquid Ba3CuSb2O9 is proposed tohave spin­orbital resonant state, which is a new quantum state of matter. Here, we report the spa­tial and temporal correlation of the orbital degree of freedom in this compound by means of the x­
ray diuse scattering method. The result shows that the orbital correlation is aected by the mag­netic interaction. This uncommon behavior supports that the new quantum phase to be estab­lished.

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