Precision Measurement Of Electric Field Based On The Trapped-ion Phonon Laser

Precision measurement of electric fields is a highly expected technology in scientific experiments and high-tech equipment fabrication.In the era of booming development of precision measurement and artificial intelligence,traditional sensors can no longer meet the demand for precision and sensitivity.The sensor based on a single trapped ion has the advantages of small size,light mass,spatial resolution,and high sensitivity,which plays an irreplaceable role in the field of precision measurement science.This thesis mainly reports on the demonstration of a mechanical analogue to an optical laser based on a single trapped-ion phonon laser.Furthermore,we found that this system is surprisingly sensitive to external electric fields.Therefore,we demonstrate the perception of the phonon laser to external signals by applying a very small DC electric field force to the system.A single 40Ca+ ion is trapped in a surface electrode ion trap and illuminated by two laser beams simultaneously.One is tuned below an atomic transition frequency,which we call the red-detuned laser,is used to damp motion of the ion.The other is tuned slightly above the atomic transition frequency,called the blue-detuned laser,and amplifies an existing motion.For some specific parameters,the forces of the red-detuned(cooling)and blue-detuned(gain)laser beam on the ion reach equilibrium and begin to oscillate with a stable amplitude.This oscillation is sustained by the stimulated emission similar to an optical laser.The simplicity of this system allows us to perform an in-depth theoretical description of it,thus matching our observations precisely.In contrast to optical laser,in our trapped-ion phonon lasers no phonons are emitted.To manipulate this system from the outside,we demonstrate the phase synchronization of the system with a tiny external signal,also known as injection locking.This is a technologically important technique,for which we have developed an electric field measurement technique to study injection locking dynamics:A tiny DC voltage is applied to the DC electrode,and the change of the DC voltage on the trapping field is measured by synchronizing the locking of the phase by injection locking.The distribution of the fluorescence signal is obtained by synchronous measurement,and the amplitude and phase of the phonon laser are obtained.In this case,we find an excellent agreement between theory and experiment and gain a unique insight into the phonon laser measurement of the electric field.The DC electric field force we introduce is very small,the electric field force used for the experiment is calculated to be 919.7 yN(1 yN=10-24N).The sensitivity of this method to measure the DC electric force is 3.32±0.50 zN/(?)(1 zN=10-21 N),which is two orders of magnitude higher than that of direct observation by optical methods with a Fresnel lens.In addition,the 3dB squeezing is applied to suppress noises,the phase uncertainty of the phonon laser is squeezing,and the sensitivity is increased to 2.38±0.47 zN/(?).Therefore,we conclude that the system is a promising sensor for detecting ultra-weak electric fields,and probably applicable to precision measurements of electric field noise.