We study the role of Franck-Condon(F-C) principle in the dynamics of a central spin system, which is coupled to an Ising chain in transverse field. The transition process of energy levels caused by the excited central...We study the role of Franck-Condon(F-C) principle in the dynamics of a central spin system, which is coupled to an Ising chain in transverse field. The transition process of energy levels caused by the excited central spin is studied to manifest the quantum critical effect through the Franck-Condon principle. The super-sensitivity of this quantum critical system is demonstrated clearly from the properties of Franck-Condon factors. We analytically show how spin numbers, coupling strength and order parameter of the Ising chain sensitively effect on the energy level populations in dynamical evolution near the critical point. This super-sensitivity and criticality are explicitly displayed in absorption spectrum.展开更多
Detecting extremely small forces helps exploring new physics quantitatively.Here we demonstrate that the phonon laser made of a single trapped ^(40)Ca^(+) ion behaves as an exquisite sensor for small force measurement...Detecting extremely small forces helps exploring new physics quantitatively.Here we demonstrate that the phonon laser made of a single trapped ^(40)Ca^(+) ion behaves as an exquisite sensor for small force measurement.We report our successful detection of small electric forces regarding the DC trapping potential with sensitivity of(2.41±0.49)zN/√Hz,with the ion only under Doppler cooling,based on the injection-locking of the oscillation phase of the phonon laser in addition to the classical squeezing applied to suppress the measurement uncertainty.We anticipate that such a single-ion sensor would reach a much better force detection sensitivity in the future once the trapping system is further improved and the fluorescence collection efficiency is further enhanced.展开更多
基金Supported by the National Basic Research Program of China under Grant Nos.2016YFA0301201 and 2014CB921403,NSFC under Grant No.11534002 and NSAF under Grant Nos.U1730449 and U1530401
文摘We study the role of Franck-Condon(F-C) principle in the dynamics of a central spin system, which is coupled to an Ising chain in transverse field. The transition process of energy levels caused by the excited central spin is studied to manifest the quantum critical effect through the Franck-Condon principle. The super-sensitivity of this quantum critical system is demonstrated clearly from the properties of Franck-Condon factors. We analytically show how spin numbers, coupling strength and order parameter of the Ising chain sensitively effect on the energy level populations in dynamical evolution near the critical point. This super-sensitivity and criticality are explicitly displayed in absorption spectrum.
基金supported by the Special Project for Research and Development in Key Areas of Guangdong Province(Grant No.2020B0303300001)National Key Research&Development Program of China(Grant No.2017YFA0304503)National Natural Science Foundation of China(Grant Nos.U21A20434,12074390,11835011,and 11734018)。
文摘Detecting extremely small forces helps exploring new physics quantitatively.Here we demonstrate that the phonon laser made of a single trapped ^(40)Ca^(+) ion behaves as an exquisite sensor for small force measurement.We report our successful detection of small electric forces regarding the DC trapping potential with sensitivity of(2.41±0.49)zN/√Hz,with the ion only under Doppler cooling,based on the injection-locking of the oscillation phase of the phonon laser in addition to the classical squeezing applied to suppress the measurement uncertainty.We anticipate that such a single-ion sensor would reach a much better force detection sensitivity in the future once the trapping system is further improved and the fluorescence collection efficiency is further enhanced.
