Journal ArticleDOI
Bose–Einstein Condensation of Collective Electron Pairs
Carlos Ramírez,Chumin Wang +1 more
TLDR
In this paper, the authors introduce the concept of collective electron pairs (CEP) through a unitary transformation of electron pairs, which achieves bosonic commutation relations at the dilute limit, being able to accumulate many of them at a single quantum state.Abstract:
Among quantum phenomena in solids at low temperatures, the superconductivity and Bose–Einstein condensation (BEC) are representatives of arising from coherent macroscopic quantum states. In this article, we discuss possible correlations between these two phenomena. It is well known that the Cooper pairs are not true bosons and then, we introduce the concept of collective electron pairs (CEP) through a unitary transformation of electron pairs. The CEP accomplish bosonic commutation relations at the dilute limit, being able to accumulate many of them at a single quantum state, in contrast to the standard Cooper pairs. An exact solution of all single CEP eigenstates is found by means of the Richardson’s equation within a multishell model. The obtained energy spectrum is used to determine the BEC temperature of CEP. In addition, we present an alternative approach to calculate the superconducting critical temperature by using the BEC formalism for a system composed by ground-state CEP, excited pairs and unpaired electrons.read more
Citations
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Bose-Einstein condensation in a gas of sodium atoms
TL;DR: The striking signature of Bose condensation was the sudden appearance of a bimodal velocity distribution below the critical temperature of ~2µK.
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Theory of Non-Hermitian Fermionic Superfluidity with a Complex-Valued Interaction.
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TL;DR: In this paper, a mean-field theory was developed to obtain a NH gap equation for order parameters, which are different from the standard BCS ones due to the inequivalence of left and right eigenstates in the NH physics.
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Absence of Superconductivity in the Pure Two-Dimensional Hubbard Model
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TL;DR: In this article, the authors revisited the notion of ''ensuremath{\eta}$-pairing states in Hubbard models and explored their connections to quantum many-body scars to discover a universal scars mechanism.
References
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Journal ArticleDOI
Theory of Superconductivity
TL;DR: In this article, a theory of superconductivity is presented, based on the fact that the interaction between electrons resulting from virtual exchange of phonons is attractive when the energy difference between the electrons states involved is less than the phonon energy, and it is favorable to form a superconducting phase when this attractive interaction dominates the repulsive screened Coulomb interaction.
Journal ArticleDOI
Observation of Bose-Einstein Condensation in a Dilute Atomic Vapor
TL;DR: A Bose-Einstein condensate was produced in a vapor of rubidium-87 atoms that was confined by magnetic fields and evaporatively cooled and exhibited a nonthermal, anisotropic velocity distribution expected of the minimum-energy quantum state of the magnetic trap in contrast to the isotropic, thermal velocity distribution observed in the broad uncondensed fraction.
Journal ArticleDOI
Bose-Einstein condensation in a gas of sodium atoms.
K. B. Davis,M.-O. Mewes,M. R. Andrews,N.J. van Druten,Dallin Durfee,D. M. Kurn,Wolfgang Ketterle +6 more
TL;DR: In this article, Bose-Einstein condensation of sodium atoms was observed in a novel trap that employed both magnetic and optical forces, which increased the phase-space density by 6 orders of magnitude within seven seconds.
Proceedings Article
Bose-Einstein condensation in a gas of sodium atoms
TL;DR: The striking signature of Bose condensation was the sudden appearance of a bimodal velocity distribution below the critical temperature of ~2µK.
Journal ArticleDOI
Doping a Mott insulator: Physics of high-temperature superconductivity
TL;DR: In this paper, a review of the physics of high-temperature superconductors from the point of view of the doping of a Mott insulator is presented, with the goal of putting the resonating valence bond idea on a more formal footing.