The quantum behavior ofa precooled cantilever can be probed highly efficiently by electrostatically coupling to a trapped ultracold ion, in which a fast cooling of the cantilever down to the ground vibrational state ...The quantum behavior ofa precooled cantilever can be probed highly efficiently by electrostatically coupling to a trapped ultracold ion, in which a fast cooling of the cantilever down to the ground vibrational state is possible. Within a simple model with an ultracold ion coupled to a cantilever with only few vibrational quanta, we solve the dynamics of the coupling system by a squeezed-state expansion technique, and can in principle obtain the exact solution of the time-evolution of the coupling system in the absence of the rotating-wave approximation. Comparing to the treatment under the rotating-wave approximation, we present a more accurate description of the quantum behavior of the cantilever.展开更多
For the first time, we derive the dispersion energy for a molecule which involves the anisotropic dipole interaction by virtue of the invariant eigen-operator method, which greatly simplifies the usual calculation if ...For the first time, we derive the dispersion energy for a molecule which involves the anisotropic dipole interaction by virtue of the invariant eigen-operator method, which greatly simplifies the usual calculation if one uses the Schroedinger equation.展开更多
We investigate the quantum dynamics of the decay of a multiple-component positronium condensate into pairs of photons. A positronium atom has four internal spin states which are interconvertible through s-wave interac...We investigate the quantum dynamics of the decay of a multiple-component positronium condensate into pairs of photons. A positronium atom has four internal spin states which are interconvertible through s-wave interactions. The quantum fields of all spin states of positroniums and photons are simulated from first principle in quasi-one-dimensional system using the truncated Wigner method. This method warrants us a full treatment of the depletion of positronium fields and the spin mixing induced by s-wave collisions between positronium atoms. Particularly,it yields the momentum spectrum of the emitted photons and the photon-photon correlations.展开更多
基金The project supported by National Natural Science Foundation of China under Grant Nos. 10474118 and 10274093 and the National Fundamental Research Program of China under Grant No. 2005CB724502
文摘The quantum behavior ofa precooled cantilever can be probed highly efficiently by electrostatically coupling to a trapped ultracold ion, in which a fast cooling of the cantilever down to the ground vibrational state is possible. Within a simple model with an ultracold ion coupled to a cantilever with only few vibrational quanta, we solve the dynamics of the coupling system by a squeezed-state expansion technique, and can in principle obtain the exact solution of the time-evolution of the coupling system in the absence of the rotating-wave approximation. Comparing to the treatment under the rotating-wave approximation, we present a more accurate description of the quantum behavior of the cantilever.
基金The project supported by the President Foundation of the Chinese Academy of Sciences and National Natural Science Foundation of China under Grant No. 10475056.
文摘For the first time, we derive the dispersion energy for a molecule which involves the anisotropic dipole interaction by virtue of the invariant eigen-operator method, which greatly simplifies the usual calculation if one uses the Schroedinger equation.
基金Supported by National Natural Science Foundation of China under Grant Nos.11434011,11674334,11421063,and 11674393National Key Basic Research Special Foundation of China under Grant No.2012CB922104+1 种基金the Fundamental Research Funds for the Central Universitiesthe Research Funds of Renmin University of China under Grant Nos.16XNLQ03 and 17XNH054
文摘We investigate the quantum dynamics of the decay of a multiple-component positronium condensate into pairs of photons. A positronium atom has four internal spin states which are interconvertible through s-wave interactions. The quantum fields of all spin states of positroniums and photons are simulated from first principle in quasi-one-dimensional system using the truncated Wigner method. This method warrants us a full treatment of the depletion of positronium fields and the spin mixing induced by s-wave collisions between positronium atoms. Particularly,it yields the momentum spectrum of the emitted photons and the photon-photon correlations.