Publication Date:
2012-06-23
Description:
In a superconductor, the ratio of the carrier density, n, to its effective mass, m*, is a fundamental property directly reflecting the length scale of the superfluid flow, the London penetration depth, lambda(L). In two-dimensional systems, this ratio n/m* (~1/lambda(L)(2)) determines the effective Fermi temperature, T(F). We report a sharp peak in the x-dependence of lambda(L) at zero temperature in clean samples of BaFe(2)(As(1)(-x)P(x))(2) at the optimum composition x = 0.30, where the superconducting transition temperature T(c) reaches a maximum of 30 kelvin. This structure may arise from quantum fluctuations associated with a quantum critical point. The ratio of T(c)/T(F) at x = 0.30 is enhanced, implying a possible crossover toward the Bose-Einstein condensate limit driven by quantum criticality.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Hashimoto, K -- Cho, K -- Shibauchi, T -- Kasahara, S -- Mizukami, Y -- Katsumata, R -- Tsuruhara, Y -- Terashima, T -- Ikeda, H -- Tanatar, M A -- Kitano, H -- Salovich, N -- Giannetta, R W -- Walmsley, P -- Carrington, A -- Prozorov, R -- Matsuda, Y -- New York, N.Y. -- Science. 2012 Jun 22;336(6088):1554-7. doi: 10.1126/science.1219821.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Physics, Kyoto University, Kyoto, Japan.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22723416" target="_blank"〉PubMed〈/a〉
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
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Chemistry and Pharmacology
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Computer Science
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Medicine
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Natural Sciences in General
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Physics
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