ANALYSIS OF IMPOSSIBILITY OF TESTING SPATIAL NONCOMMUTATIVITY USING RYDBERG ATOMS IN THE VICINITY OF SADDLE-POINT IN CROSSED ELECTRIC AND MAGNETIC FIELDS

Abstract

In relation to the current controversy over the need for an experimental test of spatial noncommutativity at the normal quantum scale, the spectra of a Rydberg electron in the vicinity of the saddle-point in a suitable combination of crossed electric and magnetic fields are investigated in both cases of commutative space and noncommutative space. Its local behavior around the saddle-point is clarified. An unbounded mode is revealed. It describes the unbounded direction along which the electron will escape the vicinity of the saddle-point, which means that it is impossible to locate electronic states. This finding indicates that the possibility of testing spatial noncommutativity in the vicinity of the saddle-point is ruled out. Because this unbounded mode applies only to states near the saddle-point, not to those from the outer well, it is suggested that if any test of spatial noncommutativity can be performed by using atoms in the crossed-field, then the test must be performed using states from the outer well, not those close to the saddle-point.