Measurement by atomic interferometry with multiple species of atoms

Apparatus for measurement by atomic interferometry comprising:

• a source of atoms (100) suitable for producing at least two sets of atoms (11, 12), with the atoms of each set of atoms that are of a species dedicated to said set of atoms and different from the species of atoms of each other set of atoms;
• means (101-103) suitable for producing conditions of atomic interference for each set of atoms (11, 12), in such a way that said conditions are produced for each set of atoms throughout a volume that is associated with said set of atoms and that contains at least one point in common with the volume associated with each other set of atoms, and are produced between a start time point and an end time point respectively before and after an intermediate time point that is common to all the sets of atoms, so as to constitute a session of measurements;
• a detection device, which is arranged to provide measurement results (P11, P12) respectively and independently for all the sets of atoms (11, 12) of each session of measurements;
• and
• an analysis unit, which is suitable for calculating at least one value of an external parameter (a) from each measurement result (P11, P12),
• in which each measurement result (P11, P12) varies according to a first function of a phase shift that appeared for the corresponding set of atoms (11, 12) during formation of the atomic interference, and said phase shift is itself a second function of the external parameter (a),
• said first function being alternately increasing and decreasing for at least a first (11) of the sets of atoms so that one and same measurement result (P11) that is obtained for said first set of atoms corresponds to several possible values of the external parameter (a) within a non-zero exploration interval, and
• said second function having, at least for one other (12) of the sets of atoms different from said first set of atoms (11), a derivative with respect to the value of the external parameter (a), that depends on at least one factor selected from a base time (T) for a sequence of interactions between the atoms and photons, and a number of photons involved in a multiphoton interaction, said sequence of interactions or said multiphoton interaction being implemented in order to form the atomic interference of said other set of atoms,
• the apparatus being characterized in that it is suitable for fixing a value of the factor so that, for one and same session of measurements, the measurement result (P12) that is obtained for said other set of atoms (12) corresponds to a single value of the external parameter (a) within the exploration interval.

Method of measurement by atomic interferometry, in which each session of measurements is executed with at least two sets of atoms (11, 12) each subjected to conditions of formation of an atomic interference, comprising:

• providing an apparatus for measurement by atomic interferometry comprising:
• a source of atoms (100) suitable for producing at least two sets of atoms (11, 12), with the atoms of each set of atoms that are of a species dedicated to said set of atoms and different from the species of atoms of each other set of atoms;
• means (101-103) suitable for producing conditions of atomic interference for each set of atoms (11, 12), in such a way that said conditions are produced for each set of atoms throughout a volume that is associated with said set of atoms and that contains at least one point in common with the volume associated with each other set of atoms, and are produced between a start time point and an end time point respectively before and after an intermediate time point that is common to all the sets of atoms, so as to constitute a session of measurements;
• a detection device, which is arranged to provide measurement results (P11, P12) respectively and independently for all the sets of atoms (11, 12) of each session of measurements;
• and
• an analysis unit, which is suitable for calculating at least one value of an external parameter (a) from each measurement result (P11, P12),
• in which each measurement result (P11, P12) varies according to a first function of a phase shift that appeared for the corresponding set of atoms (11, 12) during formation of the atomic interference, and said phase shift is itself a second function of the external parameter (a),
• said first function being alternately increasing and decreasing for at least a first (11) of the sets of atoms so that one and same measurement result (P11) that is obtained for said first set of atoms corresponds to several possible values of the external parameter (a) within a non-zero exploration interval, and
• said second function having, at least for one other (12) of the sets of atoms different from said first set of atoms (11), a derivative with respect to the value of the external parameter (a), that depends on at least one factor selected from a base time (T) for a sequence of interactions between the atoms and photons, and a number of photons involved in a multiphoton interaction, said sequence of interactions or said multiphoton interaction being implemented in order to form the atomic interference of said other set of atoms,
• the apparatus being characterized in that it is suitable for fixing a value of the factor so that, for one and same session of measurements, the measurement result (P12) that is obtained for said other set of atoms (12) corresponds to a single value of the external parameter (a) within the exploration interval;
• and
• using the apparatus to perform said method of measurement, wherein:
• the atoms of each set of atoms (11, 12) being of a species dedicated to said set of atoms and different from the species of atoms of each other set of atoms,
• method in which, for each session of measurements, said conditions are produced for each set of atoms (11, 12) throughout a volume that is associated with said set of atoms and that contains at least one point in common with the volume associated with each other set of atoms, and are produced between a start time point and an end time point respectively before and after an intermediate time point that is common to all the sets of atoms,
• and in which a measurement result (P11, P12) is obtained in each session of measurements independently for each set of atoms (11, 12), each measurement result varying according to a first function of a phase shift that appeared for the set of atoms during the formation of the atomic interference, and said phase shift itself being a second function of an external parameter (a) a value of which is sought,
• said first function being alternately increasing and decreasing for at least a first (11) of the sets of atoms so that a measurement result (P11) that is obtained for said first set of atoms corresponds to several possible values of the external parameter (a) within a non-zero exploration interval, and
• said second function having, for at least one other (12) of the sets of atoms different from said first set of atoms (11), a derivative with respect to the value of the external parameter (a), that depends on at least one factor selected from a base time (T) for a sequence of interactions between the atoms and photons, and a number of photons involved in a multiphoton interaction, said sequence of interactions or said multiphoton interaction being implemented in order to form the atomic interference of said other set of atoms,
• wherein a value of the factor is selected in order to carry out a session of measurements, so that the measurement result (P12) that is obtained for said other set of atoms (12) corresponds to a single value of the external parameter (a) within the exploration interval, so that an indetermination between several values of the external parameter (a) that exists from the measurement result (P11) obtained for the first set of atoms (11), is eliminated by correlation with the measurement result (P12) obtained for said other set of atoms (12).