Abstract
To distinguish a metal from an insulator, the Drude weight (D, zero-frequency component of conductivity) is a useful measure, as Kohn pointed out long ago: D>0(=0) for a metal (insulator). Later, Millis and Coppersmith showed that a variational wave function Ψ Q in which the key ingredient for a Mott transition (a doublon-holon binding effect) is introduced exhibits D> 0 (metallic) even for sufficiently large correlation strength, namely, a Mott transition is absent from Ψ Q. In contrast, variational Monte Carlo studies using Ψ Q confirmed, by studying relevant quantities such as doublon density d and a superconducting correlation function Pd∞, that Ψ Q undoubtedly raises a Mott transition. This contradiction has been a long-standing perplexing problem. We definitely settle this problem by adding to Ψ Q a configuration-dependent phase factor Pθ, which has been hitherto overlooked. This factor appropriately picks out a negative counterpart in D for insulators, so that vanishes. Because Pθ does not affect the quantities such as d and Pd∞, the previous results of Ψ Q on the Mott transition remain intact for Pθ Ψ Q.
Original language | English |
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Pages (from-to) | 5-8 |
Number of pages | 4 |
Journal | Physics Procedia |
Volume | 45 |
DOIs | |
Publication status | Published - 2013 |
Event | 25th International Symposium on Superconductivity, ISS 2012 - Tokyo, Japan Duration: 2012 Dec 3 → 2012 Dec 5 |
Keywords
- Drude weight
- Hubbard model
- Variational Monte Carlo
ASJC Scopus subject areas
- Physics and Astronomy(all)