A comparison of the temperature dependence of electron-positron momentum density characteristics in Tl2.2Ca2Ba2Cu 3O10.3+ δ, YBa2Cu3O 7 and La1.85Sr0.15CuO4

Y. C. Jean, H. Nakanishi, M. J. Fluss, A. L. Wachs, P. E.A. Turchi, R. H. Howell, Z. Z. Wang, R. L. Meng, P. H. Hor, Z. J. Huang, C. W. Chu

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Abstract

The temperature dependence between 2 and 300 K of the positron-electron annihilation lifetime and the electron momentum distribution from the Doppler-broadened annihilation gamma -ray energy spectrum were measured in the high-temperature superconducting material Tl2.2Ca2Ba 2Cu3O10.3+ delta. A temperature dependence is observed for the positron lifetime, below the critical temperature (124 K), suggestive of a dramatic decrease in the positron-electron overlap resulting from superconductivity. The magnitude of the observed change in the positron lifetime is the largest that the authors have seen for any high-Tc material, although the temperature dependence of the positron lifetime is similar to what they recently reported for YBa2Cu3O 7 and La1.85Sr0.15CuO4. The temperature dependence of the deduced electron momentum distribution indicates a complex but small variation in the number of low-momentum electrons available to annihilate with the delocalised positrons. This new experimental result further confirms the authors earlier suggestions of a common physics involved in high-Tc superconductivity for perovskite materials and provides evidence for the formation of superconducting electron states which are anti-correlated with the delocalised positron wavefunction for all classes of the new high-Tc materials.

Original languageEnglish
Article number004
Pages (from-to)2989-2996
Number of pages8
JournalJournal of Physics: Condensed Matter
Volume1
Issue number18
DOIs
Publication statusPublished - 1989

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Condensed Matter Physics

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Dive into the research topics of 'A comparison of the temperature dependence of electron-positron momentum density characteristics in Tl<sub>2.2</sub>Ca<sub>2</sub>Ba<sub>2</sub>Cu <sub>3</sub>O<sub>10.3+ δ</sub>, YBa<sub>2</sub>Cu<sub>3</sub>O <sub>7</sub> and La<sub>1.85</sub>Sr<sub>0.15</sub>CuO<sub>4</sub>'. Together they form a unique fingerprint.

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