Browsing by Author "Guenther, Nils Eric"

Now showing items 1-5 of 5

    • Bose polarons at finite temperature and strong coupling 

      Guenther, Nils Eric; Massignan, Pietro Alberto; Lewenstein, Maciej; Bruun, Georg (2018-02-01)
      Article
      Open Access
      A mobile impurity coupled to a weakly interacting Bose gas, a Bose polaron, displays several interesting effects. While a single attractive quasiparticle is known to exist at zero temperature, we show here that the spectrum ...

    • Dynamics of quantum mixtures 

      Guenther, Nils Eric (Universitat Politècnica de Catalunya, 2021-09-08)
      Doctoral thesis
      Open Access
      At sufficiently low temperatures, fluids of bosonic particles may undergo a phase transition, below which a Bose-Einstein condensate (BEC) forms. The BEC is one of the most fundamental concepts in many-body quantum physics ...

    • Mobile impurity in a Bose-Einstein condensate and the orthogonality catastrophe 

      Guenther, Nils Eric; Schmidt, Richard; Bruun, Georg M.; Gurarie, Victor; Massignan, Pietro Alberto (American Physical Society, 2021-01-01)
      Article
      Open Access
      We analyze the properties of an impurity in a dilute Bose-Einstein condensate (BEC). First the quasiparticle residue of a static impurity in an ideal BEC is shown to vanish with increasing particle number as a stretched ...

    • Quantized superfluid vortex dynamics on cylindrical surfaces and planar annuli 

      Guenther, Nils Eric; Massignan, Pietro Alberto; Fetter, Alexander L. (AMER PHYSICAL SOC, 2017-12-06)
      Article
      Open Access
      Superfluid vortex dynamics on an infinite cylinder differs significantly from that on a plane. The requirement that a condensate wave function be single valued upon once encircling the cylinder means that such a single ...

    • Superfluid vortex dynamics on a torus and other toroidal surfaces of revolution 

      Guenther, Nils Eric; Massignan, Pietro Alberto; Fetter, Alexander L. (American Physical Society (APS), 2020-05-04)
      Article
      Open Access
      The superfluid flow velocity is proportional to the gradient of the phase of the superfluid order parameter, leading to the quantization of circulation around a vortex core. In this work, we study the dynamics of a ...