where M is a confluent hypergeometric function and J 0 is a Bessel function of the first kind. Here, r 12 is the distance between the centers of two current loops, e is the magnitude of the electron charge, r B = 2 l B is the quantum version of the Larmor radius, and L B is the thickness of the electron gas in the direction of the magnetic field. The angular momenta of the two individual current loops are l ℏ ℏ and l ′ ′ ℏ ℏ where l + l ′ ′ = n . The inverse screening length is given by (Gaussian units)