Bose - Fermi mixtures with electrons and polaritons

A. O. Silver, M. J. Bhaseen, Martin Hohenadler +1 more

Yue Yu, S. T. Chui

We show that the electron-like and photon-like excitations may exist in a three-dimensional Bose-Fermi Hubbard model describing ultracold Bose-Fermi atom mixtures in optical lattices. In a Mott insulating phase of the Bose atoms, these excitations are stabilized by an induced repulsive interaction between 'electrons' if the Fermi atoms are nearly half filling. We suggest to create 'external electric field' so that the electron-like excitation can be observed by measuring the linear density-density response of the 'electron' gas to the 'external field' in a time-of-flight experiment of the mixture. The Fermi surface of the 'electron' gas may also be expected to be observed in the time-of-flight.

Carsten Robens, Yiqi Ni, Zoe Z. Yan +2 more

Yue Yu, S. T. Chui

We show that the 'electron' and 'photon' can emerge from a supersymmetric Hubbard model which is a non-relativistic theory of the neutral particles. The Higgs boson and 'photon' may not appear in the same phase of the phase diagram. In a Mott insulator phase of the boson, the 'electron' and 'photon' are stablized by an induced Coulomb interaction between 'electrons'. This emergent mechanism may be 'realized' in an ultracold Bose-Fermi atom mixture except the long range Coulomb interaction is repalced by a nearest neighbor one. We suggest to create 'external electric field' so that the 'electron' excitation can be observed by measuring the linear density-density response of the 'electron' gas to the 'external field' in the time flying experiment of the mixture. The Fermi surface of the 'electron' gas may also be expected to be observed in the time flying.

Cheng-Hsun Wu, Ibon Santiago, Jee Woo Park +3 more

Mistakidis, Simeon, Volosniev, Artem

The Special Issue contains theoretical and experimental works that report on studies of impurities in quantum gases, fundamental properties and universal aspects of quasiparticles and other related many-body phenomena. Particular focus is placed on the Fermi and Bose polarons.The Special Issue contains ten research articles and two reviews. M. G. Skou et al. report on the experimental observation of time dynamics of Bose polarons. Theoretical studies by H. Tajima et al., L. A. Ardila, and G. Panochko andV. Pastukhov touch upon the physics of multiple impurities, in particular, the induced impurityimpurity interactions in different spatial dimensions and the formation of multi-polaron states. G. M. Koutentakis et al. elaborate on the phenomenon of temporal orthogonality catastrophe in low dimensions. Polaritons in an electron gas are discussed by M. A. Bastarrachea-Magnani et al. M. Brooks et al. describe the emergence of anyons originating from angulons. F. Scazza et al. provide an overview of our current understanding of repulsive Bose and Fermi polarons. C. DErrico and M. G. Tarallo explicate the effects of disorder in bosonic systems. The Special Issue also includes studies of correlated atom pairs in bosonic mixtures by O. Alon, the behavior of the three-body decay rate coefficients into shallow dimers in mass-imbalanced three-atom systems by P. Giannakeas and C. H. Greene, population and angular momentum transfer in Raman-coupled BoseEinstein condensates by K. Mukherjee et al.