Frequency shifts in resonant systems

Richard M. Friedberg, Sven R. Hartmann, Jamal T. Manassah

E. A. Sagitov, Kseniia Lezhennikova, V. V. Semenov +2 more

The paper is devoted to the study of the relative influence of low-frequency and microwave signals of the system of two quantum magnetometers based on simultaneous induction of the spin generator signal on the resonance transition and the MZ-signal of the edge magnetically dependent microwave resonance. The "dressed" atom effect caused frequency shifts of low-frequency and microwave resonances is shown. The frequency shifts ratio of the spin generator to the microwave resonance was between 10 and 100, depending on the experimental conditions. The necessity of the using a circularly polarized low-frequency radio field is shown to reduce the radio-optical resonance frequency shifts caused by the mutual influence of the measuring channels of the magnetometers system.

James C. Camparo, Charles M. Klimcak

A. P. Saǐko, Г. Г. Федорук

The dynamics of a two-level spin system dressed by bichromatic radiation is studied under the conditions of double resonance when the frequency of one (microwave) field is equal to the Larmor frequency of the spin system and the frequency of the other (radio-frequency) field ω rf is close to the Rabi frequency ω 1 in a microwave field. It is shown theoretically that Rabi oscillations between dressed-spin states with the frequency ɛ are accompanied by higher-frequency oscillations at frequencies n ω rf and n ω rf ± ɛ, where n = 1, 2,.... The most intense among these are the signals corresponding to n = 1. The counter-rotating (antiresonance) components of the RF field give rise to a shift of the dressed-state energy, i.e., to a frequency shift similar to the Bloch-Siegert shift. In particular, this shift is manifested as the dependence of the Rabi-oscillation frequency ɛ on the sign of the detuning ω 1 − ω rf from resonance. In the case of double resonance, the oscillation amplitude is asymmetric; i.e., the amplitude at the sum frequency ω rf + ɛ increases, while the amplitude at the difference frequency ω rf − ɛ decreases. The predicted effects are confirmed by observations of the nutation signals of the electron paramagnetic resonance (EPR) of E ′ 1 centers in quartz and should be taken into account to realize qubits with a low Rabi frequency in solids.

Ljubomir Matulic, Peter W. Milonni, Joseph H. Eberly

Herbert C. Cheung