## Publications (3)7.73 Total impact

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**ABSTRACT:**The Seebeck and Nernst coefficients S and nu of the high-Tc superconductor YBa2Cu3Oy (YBCO) were measured in a single crystal with a hole concentration p = 0.12 in magnetic fields up to H = 28 T. For temperatures down to 9 K, nu becomes independent of field by H ˜30 T, showing that by then the Nernst signal due to superconducting fluctuations has become negligible. In this field-induced normal state, S/T and nu/T are both large and negative in the T ->0 limit. The magnitude of S/T is consistent with the small Fermi surface pocket previously detected via quantum oscillations in YBCO at a similar doping and its negative sign confirms that the pocket is electron-like. The normal-state S(T) of YBCO is remarkably similar to that of La2-xBaxCuO4, La2-x-yNdySrxCuO4 and La2-x-yEuySrxCuO4 at p ˜1/8, all four materials showing a change of sign at T ˜50 K. Given that in the latter three materials this change of sign is clearly due to the onset of spin/charge density wave (`stripe') order, we infer that a similar density-wave mechanism must cause the Fermi surface reconstruction in YBCO.03/2010; - [Show abstract] [Hide abstract]

**ABSTRACT:**The Seebeck and Nernst coefficients S and ν of the cuprate superconductor YBa2Cu3Oy (YBCO) were measured in a single crystal with doping p = 0.12 in magnetic fields up to H = 28 T. Down to T = 9 K, ν becomes independent of field by H 30 T, showing that superconducting fluctuations have become negligible. In this field-induced normal state, S/T and ν/T are both large and negative in the T → 0 limit, with the magnitude and sign of S/T consistent with the small electron-like Fermi surface pocket detected previously by quantum oscillations and the Hall effect. The change of sign in S(T) at T 50 K is remarkably similar to that observed in La2−xBaxCuO4, La2−x−yNdySrxCuO4 and La2−x−yEuySrxCuO4, where it is clearly associated with the onset of stripe order. We propose that a similar density-wave mechanism causes the Fermi surface reconstruction in YBCO.Physical Review Letters, v.104, 057005-1-057005-4 (2010). 03/2010; - [Show abstract] [Hide abstract]

**ABSTRACT:**The Seebeck and Nernst coefficients S and nu of the cuprate superconductor YBa{2}Cu{3}O{y} (YBCO) were measured in a single crystal with doping p=0.12 in magnetic fields up to H=28 T. Down to T=9 K, nu becomes independent of field by H approximately 30 T, showing that superconducting fluctuations have become negligible. In this field-induced normal state, S/T and nu/T are both large and negative in the T-->0 limit, with the magnitude and sign of S/T consistent with the small electronlike Fermi surface pocket detected previously by quantum oscillations and the Hall effect. The change of sign in S(T) at T approximately 50 K is remarkably similar to that observed in La2-xBaxCuO4, La{2-x-y}Nd{y}Sr_{x}CuO{4}, and La{2-x-y}Eu{y}Sr{x}CuO{4}, where it is clearly associated with the onset of stripe order. We propose that a similar density-wave mechanism causes the Fermi surface reconstruction in YBCO.Physical Review Letters 02/2010; 104(5):057005. · 7.73 Impact Factor

#### Publication Stats

6 | Citations | |

7.73 | Total Impact Points | |