English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We study the quantum theory of a Fermi surface coupled to a gapless bosonscalar in $D=4-\epsilon$ spacetime dimensions as a simple model for non-Fermiliquids (NFL) near a quantum phase transition. Our analysis takes into accountthe full backreaction from Landau damping of the boson, and obtains an RG flowthat proceeds through three distinct stages. Above the scale of Landau dampingthe Fermi velocity flows to zero, while the coupling evolves according to itsclassical dimension. Once damping becomes important, its backreaction leads toa crossover regime where dynamic and static damping effects compete and thefermion self-energy does not respect scaling. Below this crossover and havingtuned the boson to criticality, the theory flows to a $z=3$ scalar interactingwith a NFL. By increasing the number of bosonic flavors, the phase diagram nearthe quantum critical point interpolates between a superconducting dome fullycovering the NFL behavior, and a phase where NFL effects become importantfirst, before the onset of superconductivity. A generic prediction of thetheory is that the Fermi velocity and quasiparticle residue vanish with apower-law $\omega^\epsilon$ as the fixed point is approached. These featuresmay be useful for understanding some of the phenomenology of high $T_c$materials in a systematic $\epsilon$--expansion.

Quantum critical metals in $4-\epsilon$ dimensions