D. Ai

Publications (3)9.68 Total impact

• Source

  Available from: Stephan Rosenkranz

  Article: Electronic phase diagram of high temperature copper oxidesuperconductors

  U. Chatterjee, J. Zhao, D. Ai, S. Rosenkranz, A. Kaminski, H. Raffy, Z. Z. Li, K. Kadowaki, M. Randeria, M. R. Norman, J. C. Campuzano
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  ABSTRACT: In order to understand the origin of high-temperature superconductivity in copper oxides, we must understand the normal state from which it emerges. Here, we examine the evolution of the normal state electronic excitations with temperature and carrier concentration in Bi2Sr2CaCu2O8 using angle-resolved photoemission. In contrast to conventional superconductors, where there is a single temperature scale Tc separating the normal from the superconducting state, the high- temperature superconductors exhibit two additional temperature scales. One is the pseudogap scale T*, below which electronic excitations exhibit an energy gap. The second is the coherence scale Tcoh, below which sharp spectral features appear due to increased lifetime of the excitations. We find that T* and Tcoh are strongly doping dependent and cross each other near optimal doping. Thus the highest superconducting Tc emerges from an unusual normal state that is characterized by coherent excitations with an energy gap.
  Proceedings of the National Academy of Sciences 02/2013; 108(23). · 9.68 Impact Factor
• Article: Observation of a d-wave nodal liquid in highly underdoped Bi_2Sr_2CaCu_2O_{8+\delta}

  U. Chatterjee, M Shi, D. Ai, J Zhao, A. Kanigel, S. Rosenkranz, H. Raffy, Z. Z. Li, K Kadowaki, D. G. Hinks, Z. J. Xu, J. S. Wen, G Gu, C T Lin, H. Claus, M. R. Norman, M. Randeria, J. C. Campuzano
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  ABSTRACT: We use angle resolved photoemission spectroscopy to probe the electronic excitations of the non-superconducting state that exists between the antiferromagnetic Mott insulator at zero doping and the superconducting state at larger dopings in Bi_2Sr_2CaCu_2O_{8+\delta}. We find that this state is a nodal liquid whose excitation gap becomes zero only at points in momentum space. Despite exhibiting a resistivity characteristic of an insulator and the absence of coherent quasiparticle peaks, this material has the same gap structure as the d-wave superconductor. We observe a smooth evolution of the spectrum across the insulator-to-superconductor transition, which suggests that high temperature superconductivity emerges when quantum phase coherence is established in a non-superconducting nodal liquid.
  10/2009;
• Source

  Available from: Zhizhong Li

  Article: Observation of a d-wave nodal liquid in highly underdoped Bi2Sr2CaCu2O8+δ

  U. Chatterjee, M Shi, D. Ai, J Zhao, A. Kanigel, S. Rosenkranz, H. Raffy, Z. Z. Li, K Kadowaki, D. G. Hinks, Z. J. Xu, J. S. Wen, G Gu, C T Lin, H. Claus, M. R. Norman, M. Randeria, J. C. Campuzano