Theoretical study on rotation measurement with quantum vibration oscillators based on ion crystal in a Penning trap

In traditional mechanics, harmonic oscillators can be used to measure force, acceleration, or rotation. Herein, we describe a quantum harmonic oscillator based on a Penning-trapped calcium ion crystal. Similar to traditional oscillators, the Coriolis force-induced axial oscillation amplitude is precisely measured to determine the input velocity. We show that the magnetron motion can be controlled through the rotating wall driving and treated as the driving oscillator. The Coriolis force couples with the magnetron motion and induces vibration in the axial direction or the z direction. The center of mass motion of the ion crystal in the axial direction could be precisely detected by the entanglement between the spins of the ions and the harmonic motion through lasers. The frequency of the magnetron motion needs to meet that of the axial motion under certain conditions, and, thus, the axial motion could be tuned to the resonance peak for maximum detection signal. We provided the parameter spaces for the matching of the magnetron frequencies with those of the axial frequencies. The measurement sensitivity was calculated in detail, and results show that a rotation angular velocity of 3.0×10−9rad/s/Hz could be achieved with 10 000 ions. Amplitude sensing could reach a sensitivity of 0.4 pm/Hz. With spin squeezing, the sensitivity could be further improved.