The field theory of nonrelativistic fermions interacting via contact interactions can be used to calculate the properties of few-body systems of cold atoms confined in harmonic traps. The state-operator correspondence of nonrelativistic conformal field theory (NRCFT) shows that the energy eigenvalues (in oscillator units) of
N harmonically trapped fermions can be calculated from the scaling dimensions of
N-fermion operators in the NRCFT. They are also in one-to-one correspondence with zero energy, scale-invariant solutions to the
N-body problem in free space. We show that these two mappings of the trapped fermion problem to free space problems are related by an automorphism of the
SL(2,R) algebra of the conformal symmetry of fermions at the unitary limit. This automorphism exchanges the internal Hamiltonian of the gas with the trapping potential and hence provides a method for deriving virial theorems for trapped Fermi gases at the unitary limit. We also show that the state-operator correspondence can be applied directly in three spatial dimensions by calculating the scaling dimensions of two- and three-fermion operators and finding agreement with known exact results for energy levels of two and three trapped fermions at the unitary limit.
We consider the scattering of nonrelativistic particles in three dimensions by a contact potential $\\Omega\\hbar^2\\delta(r)/ 2\\mu r^\\alpha$ which is defined as the
ato0 limit of $\\Omega\\hbar^2\\delta(r-a)/2\\mu r^\\alpha$. It is surprising that it gives a nonvanishing cross section when
alpha=1 and
Omega=−1. When the contact potential is approached by a spherical square well potential instead of the above spherical shell one, one obtains basically the same result except that the parameter
Omega that gives a nonvanishing cross section is different. Similar problems in two and one dimensions are studied and results of the same nature are obtained.
We consider the scattering of nonrelativistic particles in three dimensions by a contact potential Ωℏ 2 δ( r )/2µ r α , which is defined as the a →0 limit of Ωℏ 2 δ( r - a )/2µ r α . It is surprising that it gives a nonvanishing cross section when α = 1 and Ω = -1. When the contact potential is approached by a spherical square well potential instead of the above spherical shell one, one obtains basically the same result except that the parameter Ω that gives a nonvanishing cross section is different. Similar problems in two and one dimensions are studied and results of the same nature are obtained.