Universität zu Köln

Patel, Aavishkar A., Strack, Philipp ORCID: 0000-0002-7040-521X and Sachdev, Subir (2015). Hyperscaling at the spin density wave quantum critical point in two-dimensional metals. Phys. Rev. B, 92 (16). COLLEGE PK: AMER PHYSICAL SOC. ISSN 2469-9969

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Abstract

The hyperscaling property implies that spatially isotropic critical quantum states in d spatial dimensions have a specific heat, which scales with temperature as T-d/z, and an optical conductivity, which scales with frequency as omega((d- 2)/z) for omega >> T, where z is the dynamic critical exponent. We examine the spin density wave critical fixed point of metals in d = 2 found by Sur and Lee [Phys. Rev. B 91, 125136 (2015)] in an expansion in epsilon = 3 - d. We find that the contributions of the hot spots on the Fermi surface to the optical conductivity and specific heat obey hyperscaling (up to logarithms), and agree with the results of the large N analysis of the optical conductivity by Hartnoll et al. [ Phys. Rev. B 84, 125115 (2011)]. With a small bare velocity of the boson associated with the spin density wave order, there is an intermediate energy regime where hyperscaling is violated with d -> d(t), where d(t) = 1 is the number of dimensions transverse to the Fermi surface. We also present a Boltzmann equation analysis which indicates that the hot-spot contribution to the dc conductivity has the same scaling as the optical conductivity, with T replacing omega.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Patel, Aavishkar A. UNSPECIFIED UNSPECIFIED UNSPECIFIED Strack, Philipp UNSPECIFIED orcid.org/0000-0002-7040-521X UNSPECIFIED Sachdev, Subir UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-389991
DOI:	10.1103/PhysRevB.92.165105
Journal or Publication Title:	Phys. Rev. B
Volume:	92
Number:	16
Date:	2015
Publisher:	AMER PHYSICAL SOC
Place of Publication:	COLLEGE PK
ISSN:	2469-9969
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language NONZERO-TEMPERATURE TRANSPORT; FERMION MODEL; NORMAL-STATE Multiple languages Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter Multiple languages
URI:	http://kups.ub.uni-koeln.de/id/eprint/38999