“Homes's law”的意思、由来-开放百科全书

In superconductivity, Homes's law is an empirical relation that states that a superconductor's

critical temperature (T_c) is proportional to the strength of the superconducting state for temperatures well below T_c close to zero temperature (also referred to as the fully formed superfluid density,

) multiplied by the electrical resistivity

measured just above the critical temperature. In cuprate high-temperature superconductors the relation follows the form

Many novel superconductors are anisotropic, so the resistivity and the superfluid density are

Note that this expression assumes that the conductivity and temperature have both been recast in units

(or s⁻²); the constant is dimensionless. The expected form for a BCS dirty-limit superconductor

The law is named for physicist Christopher Homes and was first presented in the July 29, 2004 edition of Nature,^[1] and was the subject of a News and Views article by Jan Zaanen in the same issue^[2] in which he speculated that the high transition temperatures observed in the

cuprate superconductors are because the metallic states in these materials are as viscous as

permitted by the laws of quantum physics. A more detailed version of this scaling relation subsequently appeared in

Physical Review B in 2005,^[3] in which it was argued that any material that falls on the scaling line is likely in the

dirty limit (superconducting coherence length ξ₀ is much greater than the normal-state mean-free path l,

ξ₀≫ l); however, a paper by Vladimir Kogan in Physical Review B in 2013 has shown that the

suggesting that only materials in the clean limit (ξ₀≪ l) will fall off of this scaling line.

Francis Pratt and Stephen Blundell have argued that Homes's law is violated in the organic superconductors. This

work was first presented in Physical Review Letters in March 2005.^[5] On the other hand, it has been recently demonstrated by Sasa Dordevic and coworkers that

if the dc conductivity and the superfluid density are measured on the same sample at the same time using either infrared

or microwave impedance spectroscopy, then the organic superconductors do indeed fall on the universal scaling line,

along with a number of other exotic superconductors. This work was published in Scientific Reports in

References

1. ^{{cite journal|author = C. C. Homes|title = A universal scaling relation in high-temperature superconductors| journal = Nature| volume = 430| pages = 539–541| year = 2004| doi = 10.1038/nature02673|pmid = 15282599|arxiv = cond-mat/0404216 |bibcode = 2004Natur.430..539H| issue=6999|display-authors=etal}}
2. ^{{cite journal|first=Jan|last=Zaanen|authorlink=Jan Zaanen| title = Superconductivity: Why the temperature is high| journal = Nature|volume = 430| pages = 512–513| year = 2004 | doi = 10.1038/430512a |pmid=15282588|bibcode = 2004Natur.430..512Z | issue=6999}}
3. ^{{cite journal|author1=C. C. Homes |author2=S. V. Dordevic |author3=T. Valla |author4=M. Strongin |title = Scaling of the superfluid density in high-temperature superconductors|journal = Phys. Rev. B|volume = 72|issue=13 |pages = 134517|year = 2005|doi = 10.1103/PhysRevB.72.134517|arxiv = cond-mat/0410719 |bibcode = 2005PhRvB..72m4517H }}
4. ^{{cite journal|author = V. G. Kogan|title = Homes scaling and BCS| journal = Phys. Rev. B| volume = 87|issue = 22| pages = 220507(R)| year = 2013|doi = 10.1103/PhysRevB.87.220507| arxiv = 1305.3487|bibcode = 2013PhRvB..87v0507K }}
5. ^{{cite journal|author1=F. L. Pratt |author2=S. J. BLundell | title = Universal Scaling Relations in Molecular Superconductors| journal = Phys. Rev. Lett. |volume = 94|issue=9 | pages = 097006| year = 2005|doi = 10.1103/PhysRevLett.94.097006| arxiv = cond-mat/0411754|bibcode = 2005PhRvL..94i7006P | pmid=15783993}}
6. ^{{cite journal|author1=S. V. Dordevic |author2=D. N. Basov |author3=C. C. Homes | title = Do organic and other exotic superconductors fail universal scaling relations?| journal = Sci. Rep.|volume = 3| pages = 1713| year = 2012| doi = 10.1038/srep01713| arxiv = 1305.0019|bibcode = 2013NatSR...3E1713D }}