Complex Langevin simulation of quantum vortices in a Bose-Einstein condensate

Abstract

The ab-initio simulation of quantum vortices in a Bose-Einstein condensate is performed by adopting the complex Langevin techniques. We simulate the nonrelativistic boson field theory at finite chemical potential under rotation. In the superfluid phase, vortices are generated above a critical angular velocity and the circulation is clearly quantized even in the presence of quantum fluctuations.

Interacting Bosons at Finite Angular Momentum Via Complex Langevin

“…We then showed preliminary results for a system of interacting 2+1 dimensional bosons at finite angular momentum, for which we extracted the expectation value of L z and the moment of inertia as a function of the angular velocity. It is worth noting that previous works have explored the behavior of bosons at finite angular momentum with CL, as applied to the (3+1)-dimensional problem [14]. The results shown in the previous section are promising, and further study is underway.…”

“…Outside of relativistic physics, CL is just emerging as a useful method. A 2015 paper discusses the results of applying CL to bosonic quantum field theory in a rotating frame to circumvent the sign problem [14]. More recently, work on fermionic systems in one spatial dimension calculated the density and pressure equations of state, comparing CL results with third-order lattice perturbation theory [15].…”

Thermodynamics of spin-orbit-coupled bosons in two dimensions from the complex Langevin method

“…One alternative in this scenario is the complex Langevin technique, which has been used to study theories with sign problems such as those with repulsive interactions [24] as well as polarized [25,26] and massimbalanced fermions [27] (see Ref. [28] for a review), finite density QCD with staggered quarks [29][30][31][32], random matrix models [33,34], rotating bosons [35,36], superstringinspired matrix models [37], among others.…”

String confinement in two-form lattice gauge theory

“…Although the vortex string is frequently studied in semiclassical analysis, it misses quantum fluctuation. Firstprinciples analysis is necessary to take into account quantum fluctuation, e.g., percolation [13][14][15][16] and superposition [17,18]. Such an analysis is particularly important near phase transitions or in finite volumes, where quantum fluctuation is non-negligible.…”