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 Tools annual

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 monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

This review gives a rather general discussion of high temperaturesuperconductors as an example of a strongly correlated material. The argumentis made that in view of the many examples of unconventional superconductorsdiscovered in the past twenty years, we should no longer be surprised thatsuperconductivity emerges as a highly competitive ground state in systems whereCoulomb repulsion plays a dominant role. The physics of the cuprates isdiscussed, emphasizing the unusual pseudogap phase in the underdoped region. Itis argued that the resonating valence bond (RVB) picture, as formulated usinggauge theory with fermionic and bosonic matter fields, gives an adequatephysical understanding, even though many details are beyond the powers ofcurrent calculational tools. The recent discovery of quantum oscillations in ahigh magnetic field is discussed in this context. Meanwhile, the problem of thequantum spin liquid (a spin system with antiferromagnetic coupling whichrefuses to order even at zero temperature) is a somewhat simpler version of thehigh $T_c$ problem where significant progress has been made recently. It isunderstood that the existence of matter fields can lead to de-confinement ofthe U(1) gauge theory in 2+1 dimensions, and novel new particles (calledfractionalized particles), such as fermionic spinons which carry spin ${1\over2}$ and no charge, and gapless gauge bosons can emerge to create a new criticalstate at low energies. We even have a couple of real materials where such ascenario may be realized experimentally. The article ends with answers toquestions such as: what limits $T_c$ if pairing is driven by an electronicenergy scale? why is the high $T_c$ problem hard? why is there no consensus?and why is the high $T_c$ problem important?

From high temperature supercondutivity to quantum spin liquid: progress in strong correlation physics