Are preformed Cooper pairs the cause for the pseudogap in superconductors?

Mamedov, T. A.; Llano, M. de

doi:10.1080/14786435.2014.979903

Cited by 9 publications

(5 citation statements)

References 45 publications

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“…In refs. [6,34,35] the use of (6) as a trial for

\overset{˚}{scriptE}

led to the pseudogap

T^{*}

and superconducting critical

T_{normalc}

temperatures which actually occur in HTSCs.…”

Section: Preformed 2 E ‐Bosonsmentioning

confidence: 99%

“…[6]; details are found in refs. [34,35,38]. The choice of

A = a_{k ↑}

and

B = a_{{boldk}^{'} ↑}^{+}

in (9) results in the single‐electron GF

{⟨ ⟨ a_{k ↑} | a_{{boldk}^{'} ↑}^{+} ⟩ ⟩}_{ω} = δ_{k k'} {[ℏ ω - ξ_{boldk} - Σ_{boldk} (ω)]}^{- 1}

with

Σ_{boldk} (ω)

the self energy of interacting electrons.…”

Section: Unpaired‐electron Energies and Boson Numbers For T > T Normalcmentioning

confidence: 99%

“…[6]; details are found in refs. [34,35,38]. The choice of A ¼ a k" and B ¼ a þ k 0 " in ( 9) results in the single-electron GF…”

Section: Unpaired-electron Energies and Boson Numbers For T > T Cmentioning

confidence: 99%

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Electronic Structure of Cuprates in a Boson–Fermion Mixture Theory

Mamedov

Llano

2021

Physica Status Solidi (b)

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In a nearly‐filled energy band where scattering of electrons is hampered, a pairing interaction between two electrons and quanta in a solid (e.g., phonons or spin‐resonances or some other excitation of electronic origin) can still occur in the s‐channel where a field quantum mediates the coalescence of two fermions into a new composite particle. By describing the attractively‐interacting electrons as a gas mixture of individual electrons plus bosons made up of two electrons, the dependence on momentum of the energy of single electrons is investigated. When the net interaction BCS dimensionless coupling constant λ and the ratio with the maximum energy ℏ ω D of a quantum mediating the pairing to the Fermi energy E normalF increases, the coalescence of electrons at temperatures higher than the Bose–Einstein condensation (BEC) temperature T normalc of bosons leads to the appearance of steep (waterfall‐like) changes in the high‐energy electron spectrum of the binary boson–fermion (BF) gas mixture. These waterfall‐like anomalies seen in high‐ T normalc superconductors (HTSCs) are in fact a characteristic property of a BF gas mixture and reflect the splitting of the conduction band into two subbands emerging as the number N normalB of two‐electron bosons increases.

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“…In refs. [6,34,35] the use of (6) as a trial for

\overset{˚}{scriptE}

led to the pseudogap

T^{*}

and superconducting critical

T_{normalc}

temperatures which actually occur in HTSCs.…”

Section: Preformed 2 E ‐Bosonsmentioning

confidence: 99%

“…[6]; details are found in refs. [34,35,38]. The choice of

A = a_{k ↑}

and

B = a_{{boldk}^{'} ↑}^{+}

in (9) results in the single‐electron GF

{⟨ ⟨ a_{k ↑} | a_{{boldk}^{'} ↑}^{+} ⟩ ⟩}_{ω} = δ_{k k'} {[ℏ ω - ξ_{boldk} - Σ_{boldk} (ω)]}^{- 1}

with

Σ_{boldk} (ω)

the self energy of interacting electrons.…”

Section: Unpaired‐electron Energies and Boson Numbers For T > T Normalcmentioning

confidence: 99%

See 1 more Smart Citation

Electronic Structure of Cuprates in a Boson–Fermion Mixture Theory

Mamedov

Llano

2021

Physica Status Solidi (b)

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“…This simplification can be lifted-see Ref. [22][23][24][25] where excited bosons with K = 0 are not excluded in the interaction Hamiltonian ofĤ −μN which can then be dealt with via two-time Green functions.…”

Section: Gbec Equationsmentioning

confidence: 99%

Multicondensate Superconductivity in a Generalized BEC Formalism with Hole Cooper Pairs

Chávez

Grether

Llano

2014

J Supercond Nov Magn

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We sketch the generalized Bose-Einstein condensation (GBEC) formalism of a ternary boson-fermion (BF) model to study the critical transition temperature T c of a superconductor. This ternary model contrasts with the more familiar binary models of, e.g., Eagles, Ranninger et al., T.D. Lee et al., etc. The fermions are unpaired electrons (e) or, without loss of generality, holes (h); the bosons are Cooper pairs (CPs) each of both these fermions. In essence, the GBEC is a statistical model, as is the Bardeen-Cooper-Schrieffer (BCS) theory also, and yields three condensed chemically-and thermodynamically-stable phases: two pure phases, one for electron Cooper pairs (2e-CPs), and the other for hole Cooper pairs (2h-CPs), along with a mixed phase in arbitrary proportions of each of the two pure phases. The explicit inclusion of 2h-CPs dramatically increases the T c of a superconductor with respect to BCS besides including as special cases all known statistical models of superconductors.

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“…Preformed pairs are correlated above T c only on some short temporal τ φ and spatial l φ scales [21][22][23]. For this reason, the superconducting fluctuations are manifested in very peculiar way [24]. Their influence on the single particle spectrum is manifested by: a) two Bogoliubov-type branches and b) additional in-gap states that are over-damped (have a short life-time).…”

mentioning

confidence: 99%

Quasiparticle states driven by a scattering on the preformed electron pairs

Domański¹

2016

Condens. Matter Phys.

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We analyze evolution of the single particle excitation spectrum of the underdoped cuprate superconductors near the anti-nodal region, considering temperatures below and and above the phase transition. We inspect the phenomenological self-energy that reproduces the angle-resolved-photoemission-spectroscopy (ARPES) data and we show that above the critical temperature, such procedure implies a transfer of the spectral weight from the Bogoliubov-type quasiparticles towards the in-gap damped states. We also discuss some possible microscopic arguments explaining this process.

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Are preformed Cooper pairs the cause for the pseudogap in superconductors?

Cited by 9 publications

References 45 publications

Electronic Structure of Cuprates in a Boson–Fermion Mixture Theory

Electronic Structure of Cuprates in a Boson–Fermion Mixture Theory

Multicondensate Superconductivity in a Generalized BEC Formalism with Hole Cooper Pairs

Quasiparticle states driven by a scattering on the preformed electron pairs

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