Dual interferometry with a tunable point of minimum magnetic sensitivity*

The clock transition is well known for its minimum magnetic sensitivity at B$=$0. The hyperfine transition between F$=$1, m$=$-1 and F$=$2, m$=$1 in 87Rb also shows a point of minimum magnetic sensitivity but it happens at a field of 3.2 Gauss. An interferometer that uses a mixture of the previous two transitions gives a minimum of magnetic sensitivity at a tunable value of the magnetic field between 0 and 3.2 Gauss. The desired magnetic field value can be selected by varying the population in each transition. The relative populations are controlled with a microwave pulse joining states in both interferometers.