Crystallography of color superconductivity

By J. Bowers, Kumbakonam R. Rajagopal. 2002

135 citations recorded by the source corpus.

We develop the Ginzburg-Landau approach to comparing different possible crystal structures for the crystalline color superconducting phase of QCD, the QCD incarnation of the Larkin-Ovchinnikov-Fulde-Ferrell phase. In this phase, quarks of different flavor with differing Fermi momenta form Cooper pairs with nonzero total momentum, yielding a condensate that varies in space like a sum of plane waves. We work at zero temperature, as is relevant for compact star physics. The Ginzburg-Landau approach predicts a strong first-order phase transition (as a function of the chemical potential difference between quarks) and for this reason is not under quantitative control. Nevertheless, by organizing the comparison between different possible arrangements of plane waves (i.e., different crystal structures) it provides considerable qualitative insight into what makes a crystal structure favorable. Together, the qualitative insights and the quantitative, but not controlled, calculations make a compelling case that the favored pairing pattern yields a condensate which is a sum of eight plane waves forming a face-centered cubic structure. They also predict that the phase is quite robust, with gaps comparable in magnitude to the BCS gap that would form if the Fermi momenta were degenerate. These predictions may be tested in ultracold gases made of fermionic atoms. In a QCD context, our results lay the foundation for a calculation of vortex pinning in a crystalline color superconductor, and thus for the analysis of pulsar glitches that may originate within the core of a compact star.

Subfields: Atomic and Molecular Physics, and Optics, Condensed Matter Physics

View Paper: https://www.semanticscholar.org/paper/55da2585da732fea3fbaa3fc4097b7f1c467b2d3

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Atomic and Molecular Physics, and Optics

1. M. Zwierlein
2. C. Pfleiderer
3. W. Ketterle
4. G. Strinati
5. R. Casalbuoni
6. P. Schuck
7. G. Roepke
8. G. Nardulli

In Condensed Matter Physics

1. C. Pfleiderer
2. M. Zwierlein
3. G. Strinati
4. R. Casalbuoni
5. P. Schuck
6. G. Roepke
7. W. Ketterle
8. G. Nardulli

Citations in the corpus

• The BCS–BEC crossover: From ultra-cold Fermi gases to nuclear systems (2018, background): “[121] to study the FFLO phase in the context of color superconductivity in QCD (for a review, see Refs.”
• Superconducting phases of f -electron compounds (2009, background): “…in spatial modulations of the superconductivity in real space, for which the order parameter may be given in general as ∆(~r) = ∑M m=1 ∆m exp i~qm·~r (Bowers and Rajagopal, 2002; Combescot and Tonini, 2005; Fulde and Ferrell, 1964; Larkin and Ovchinnikov, 1965; Mora and Combescot, 2004, 2005;…”
• Inhomogeneous superconductivity in condensed matter and QCD (2003, methodology): “We begin by performing the Ginzburg-Landau expansion at T50 for a general inhomogeneous gap function (Larkin and Ovchinnikov, 1964; Bowers and Rajagopal, 2002).”
• Making, probing and understanding ultracold Fermi gases (2008, background): “) still remembers vividly how an MIT particle physics colleague, Krishna Rajagopal, asked him about the possibility of realizing pairing between fermions with different Fermi energies (see [96]), even before condensation and superfluidity in balanced mixtures had become possible.”