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Nernst effect in high temperature su...

Princeton University.

Nernst effect in high temperature superconductors.

Record Type:	Electronic resources : Monograph/item
Title/Author:	Nernst effect in high temperature superconductors.
Author:	Wang, Yayu.
Description:	170 p.
Notes:	Adviser: Nai-Phuan Ong.
Notes:	Source: Dissertation Abstracts International, Volume: 65-08, Section: B, page: 4079.
Contained By:	Dissertation Abstracts International65-08B.
Subject:	Physics, Condensed Matter.
Online resource:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3143558
ISBN:	0496013351

Nernst effect in high temperature superconductors.
Wang, Yayu.

Nernst effect in high temperature superconductors. - 170 p.

Adviser: Nai-Phuan Ong.

Thesis (Ph.D.)--Princeton University, 2004.

In the severely underdoped regime (x < 0.12), some new features become apparent and they imply that the vortex Nernst signal is comprised of two distinct contributions. The first is from coherent regions with long range phase coherence and relatively low upper critical field, more like the superconducting phase; the second is from phase incoherent regions with much larger field scales, indicative of the pseudogap phase. As temperature rises, the superconducting phase gives weight to the pseudogap phase. Moreover, the upper critical field Hc2 of the superconducting phase scales with the onset temperature Tnonset of the vortex-like excitations.

ISBN: 0496013351Subjects--Topical Terms:

226939
Physics, Condensed Matter.

Nernst effect in high temperature superconductors.
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100 0 $a Wang, Yayu. $3 227963
245 1 0 $a Nernst effect in high temperature superconductors.
300 $a 170 p.
500 $a Adviser: Nai-Phuan Ong.
500 $a Source: Dissertation Abstracts International, Volume: 65-08, Section: B, page: 4079.
502 $a Thesis (Ph.D.)--Princeton University, 2004.
520 # $a In the severely underdoped regime (x < 0.12), some new features become apparent and they imply that the vortex Nernst signal is comprised of two distinct contributions. The first is from coherent regions with long range phase coherence and relatively low upper critical field, more like the superconducting phase; the second is from phase incoherent regions with much larger field scales, indicative of the pseudogap phase. As temperature rises, the superconducting phase gives weight to the pseudogap phase. Moreover, the upper critical field Hc2 of the superconducting phase scales with the onset temperature Tnonset of the vortex-like excitations.
520 # $a Our first finding is the existence of vortex-like excitations at temperatures much higher than Tc0, the zero filed transition temperature, in the underdoped cuprates. This result suggests that in the putative normal state of cuprates, although bulk Meissner effect is absent and resistivity looks normal, the amplitude of the Cooper pairing is still sizable. The transition at Tc0 is driven by the loss of long range phase coherence rather than the disappearance of superconducting condensate.
520 # $a The high field Nernst effect offers a reliable way to determine the upper critical field Hc2 of high Tc cuprates and many unusual properties are uncovered. For cuprates with relatively large hole density (x > 0.15), we found that H c2 is almost temperature independent for T < Tc0. This is in strong contrast to the Hc2 - T relation of conventional superconductors. Moreover, using a scaling analysis, we have demonstrated that H c2 increases with decreasing hole density x in this doping range, implying a stronger pairing potential at lower doping.
520 # $a This thesis presents a study of the Nernst effect in high temperature superconductors. The vortex Nernst measurements have been carried out on various high Tc cuprates to high magnetic fields. These results provide vital information about the properties and relations of the pseudogap phase and superconducting phase in high Tc superconductors.
590 $a School code: 0181.
650 # 0 $a Physics, Condensed Matter. $3 226939
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710 0 # $a Princeton University. $3 212488
773 0 # $g 65-08B. $t Dissertation Abstracts International
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790 1 0 $a Ong, Nai-Phuan, $e advisor
791 $a Ph.D.
792 $a 2004
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