相关论文: Theory for Quartet Condensation in Fermi Systems w…
The onset of quartetting, i.e. alpha-particle condensation, in symmetric nuclear matter is studied with the help of an in-medium modified four nucleon equation. It is found that at very low density quartetting wins over pairing, because of…
Four-particle correlations in fermion systems at finite temperatures are investigated with special attention to the formation of a condensate. Instead of the instability of the normal state with respect to the onset of pairing described by…
The theory for condensation of higher fermionic clusters is developed. Fully selfconsistent nonlinear equations for the quartet order parameter in strongly coupled fermionic systems are established and solved. The breakdown of the…
The $\alpha$-particle condensate in nuclei is a novel state described by a product state of $\alpha$'s, all with their c.o.m. in the lowest 0S orbit. We demonstrate that a typical $\alpha$-particle condensate is the Hoyle state…
At low densities, with decreasing temperatures, in symmetric nuclear matter alpha-particles are formed, which eventually give raise to a quantum condensate with four-nucleon alpha-like correlations (quartetting). Starting with a model of…
A comparison of pairing properties in cuprates and nuclear matter is briefly discussed. Quartet (alpha-particle) condensation is a very important aspect of nuclear physics. The physics of the Hoyle state in 12 C will be outlined and its…
A general theory for the condensation of strongly bound quartets in infinite nuclear matter is presented. Critical temperatures for symmetric and asymmetric nuclear matter are evaluated. A fully nonlinear theory for the quartet order…
The critical temperature for $\alpha$-particle condensation in nuclear matter with Fermi surface imbalance between protons and neutrons is determined. The in-medium four-body Schr\"odinger equation, generalizing the Thouless criterion of…
Alpha-particle (quartet) condensation in homogeneous spin-isospin symmetric nuclear matter is investigated. The usual Thouless criterion for the critical temperature is extended to the quartet case. The in-medium four-body problem is…
When the density of a nuclear system is decreased, homogeneous states undergo the so-called Mott transition towards clusterised states, e.g. alpha clustering, both in nuclei and in nuclear matter. Here we investigate such a quantum phase…
In this article we review the present status of alpha clustering in nuclear systems. First of all, an important aspect is condensation in nuclear matter. Second, the alpha container model, recently been proposed by…
Our present understanding of the structure of the Hoyle state in $^{12}$C and other near-threshold states in $\alpha$-conjugate nuclei is reviewed in the framework of the $\alpha$-condensate model. The $^{12}$C Hoyle state, in particular,…
$\alpha$ particle condensation is a novel state in nuclear systems. We briefly review the present status on the study of $\alpha$ particle condensation and address the open problems in this research field: $\alpha$ particle condensation in…
The Bose-Einstein condensation of $\alpha$ partciles in the multicomponent environment of dilute, warm nuclear matter is studied. We consider the cases of matter composed of light clusters with mass numbers $A\leq 4$ and matter that in…
Possibility of a quartet superfluidity in fermionic systems is studied as a new aspect of atomic gas at ultra low temperatures. The four-fold degeneracy of hyperfine state and moderate coupling is indispensable for the quartet superfluidity…
In nature, everything occurs at finite temperature and quantum phase transitions (QPTs) cannot be an exception. Nevertheless, they are still mainly discussed and formulated at zero temperature. We show that the condensation QPTs recently…
The phenomenon of quartet condensation in the ground state of an isovector pairing Hamiltonian for an even-even $N=Z$ system is investigated. For this purpose we follow the evolution of the ground state from an unperturbed regime up to a…
The fragmentation of quasi-projectiles from the nuclear reaction $^{40}$Ca+$^{12}$C at 25 MeV/nucleon was used to produce excited states candidates to $\alpha$-particle condensation. Complete kinematic characterization of individual decay…
We elucidate the fate of neighboring two and three-$\alpha$ particles in cold neutron matter by focusing on an analogy between such $\alpha$ systems and Fermi polarons realized in ultracold atoms. We describe in-medium excitation properties…
Electron pairing at low temperatures leads to superconductivity. A fundamental question is whether more complex states - characterized by order in four-electron composite objects, termed electron quadrupling or composite order - can exist…