Abstract
A zero-gap state (ZGS) has been found in a bulk system of two-dimensional organic conductor, α-(BEDT-TTF)2I3 salt which consists of four sites of donor molecules in a unit cell. In the present paper, the characteristic of the ZGS is analyzed in detail and the electronic properties are examined in the vicinity of the Dirac point where the conduction and valence bands degenerate to form the zero-gap. The eigenvectors of the energy band have four components of respective sites, where two of them correspond to inequivalent sites and the other two correspond to equivalent sites. It is shown that the former exhibits an exotic momentum dependence around the contact point and the latter shows almost a constant dependence. The density of states of each site close to the Dirac point is calculated to demonstrate the temperature dependence of the local magnetic susceptibility and the local nuclear magnetic relaxation rate. Further, the robust property of the ZGS against the anion potential is also shown by using the second-order perturbation.
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References
T. Ishiguro, K. Yamaji, G. Saito, Organic Superconductors, 2nd edn. (Springer-Verlag, Berlin, 1998)
K. Bender, I. Hennig, D. Schweitzer, K. Dietz, H. Endres, H.J. Keller, Mol. Cryst. Liq. Cryst. 108, 359 (1984)
T. Mori, A. Kobayashi, T. Sasaki, H. Kobayashi, G. Saito, H. Inokuchi, Chem. Lett. 957 (1984)
A. Kobayashi, S. Katayama, K. Noguchi, Y. Suzumura, J. Phys. Soc. Jpn 73, 3135 (2004)
S. Katayama, A. Kobayashi, Y. Suzumura, J. Phys. Soc. Jpn 75, 054705 (2006)
R. Kondo, S. Kagoshima, J. Harada, Rev. Sci. Instrum. 76, 093902 (2005)
A. Kobayashi, S. Katayama, Y. Suzumura, H. Fukuyama, J. Phys. Soc. Jpn 76, 034711 (2007)
N. Tajima, M. Tamura, Y. Nishio, K. Kajita, Y. Iye, J. Phys. Soc. Jpn 69, 543 (2000)
N. Tajima, S. Sugawara, M. Tamura, R. Kato, Y. Nishio, K. Kajita, Europhys. Lett. 80, 47002 (2007)
A. Kobayashi, Y. Suzumura, H. Fukuyama, J. Phys. Soc. Jpn 77, 064718 (2008)
S. Katayama, A. Kobayashi, Y. Suzumura, J. Phys. Soc. Jpn 75, 023708 (2006)
K.S. Novoselov, A.K. Geim, S.V. Morozov, D. Jiang, M.I. Katsnelson, I.V. Grigorieva, S.V. Dubonos, A.A. Firsov, Nature 438, 197 (2005)
Y. Zhang, Y.W. Tan, H.L. Stormer, P. Kim, Nature 438, 201 (2005)
P.R. Wallace, Phys. Rev. 71, 622 (1947)
H. Ajiki, T. Ando, J. Phys. Soc. Jpn 62, 1255 (1993)
T. Ando, J. Phys. Soc. Jpn 74, 777 (2005)
M.O. Goerbig, J.-N. Fuchs, G. Montambaux, F. Piechon, Phys. Rev. B 78, 045415 (2008)
T. Ando, T. Nakanishi, R. Saito, J. Phys. Soc. Jpn 67, 2857 (1998)
Y. Zheng, T. Ando, Phys. Rev. B 65, 245420 (2002)
V.P. Gusynin, S.G. Sharapov, Phys. Rev. B 73, 245411 (2006)
H. Fukuyama, J. Phys. Soc. Jpn 76, 043711 (2007)
K. Nomura, A.H. MacDonald, Phys. Rev. Lett. 98, 076602 (2007)
N.H. Shon, T. Ando, J. Phys. Soc. Jpn 67, 2421 (1998)
H. Kumazaki, D.S. Hirashima, J. Phys. Soc. Jpn 75, 053707 (2006)
N.M.R. Peres, F. Guinea, A.H. Castro Neto, Phys. Rev. B 73, 125411 (2006)
V.V. Cheianov, V.I. Fal’ko, Phys. Rev. Lett. 97, 226801 (2006)
T.O. Wehling, A.V. Balatsky, M.I. Katsnelson, A.I. Lichtenstein, K. Scharnberg, R. Wiesendanger, Phys. Rev. B 75, 125425 (2007)
P.A. Wolff, J. Phys. Chem. Solids 25, 1057 (1964)
H. Fukuyama, R. Kubo, J. Phys. Soc. Jpn 28, 570 (1970)
B.A. Bernevig, T.L. Hughes, S.C. Zhang, Science 314, 1757 (2006)
S. Moroto, K. Hiraki, Y. Takano, Y. Kubo, T. Takahashi, H.M. Yamamoto, T. Nakamura, J. Phys. IV France 114, 339 (2004)
Y. Takano, K. Hiraki, H.M. Yamamoto, T. Nakamura, T. Takahashi, Synth. Met. 120, 1081 (2001)
T. Kakiuchi, Y. Wakabayashi, H. Sawa, T. Takahashi, T. Nakamura, J. Phys. Soc. Jpn 76, 113702 (2007)
T. Takahashi, Y. Takano, private communication
R. Kondo, S. Kagoshima, N. Tajima, R. Kato, preprint
H. Kino, T. Miyazaki, J. Phys. Soc. Jpn 75, 034704 (2006)
J.M. Luttinger, W. Kohn, Phys. Rev. 97, 869 (1955)
S. Katayama, A. Kobayashi, Y. Suzumura, J. Phys. Conf. Series 132, 012003 (2008)
A. Kobayashi, S. Katayama, Y. Suzumura, J. Phys. Soc. Jpn 74, 2897 (2005)
S. Komaba, Master thesis, Nagoya University, 2008
T. Moriya, J. Phys. Soc. Jpn 18, 516 (1963)
Y. Suzumura, J. Phys. Soc. Jpn 58, 2642 (1989)
S. Katayama, A. Kobayashi, Y. Suzumura, J. Phys. Soc. Jpn 77, 014710 (2008)
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Katayama, S., Kobayashi, A. & Suzumura, Y. Electronic properties close to Dirac cone in two-dimensional organic conductor α-(BEDT-TTF)2I3 . Eur. Phys. J. B 67, 139–148 (2009). https://doi.org/10.1140/epjb/e2009-00020-0
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DOI: https://doi.org/10.1140/epjb/e2009-00020-0