Coupled Q-oscillators as a model for vibrations of polyatomic molecules

Realization of nonlinear oscillators with a trapped ion

We consider a trapped ion with a quantized center-of-mass motion in 2D trap potential. With external laser fields the effective (non)linear coupling of two orthogonal vibrational modes can be established via stimulated Raman transition. Nonclassical vibrational states such as squeezed states or two-mode entangled states (Schroedinger cat-like states) can be generated. When the vibrational modes are entangled with internal energy levels the Greenberger-Horne-Zeilinger (GHZ) states can be prepared.

Accurate ro-vibrational spectroscopy of diatomic molecules in a Morse oscillator potential

This work presents the bound-state spectra of Morse oscillator, which remains one of the oldest important model potentials for molecules. Accurate ro-vibrational energies are obtained by means of a generalized pseudospectral method that offers an optimal, non-uniform discretization of the radial grid. Both s-wave ($\ell=0$) and rotational ($\ell \neq 0$) states for low and high quantum numbers are calculated for four representative diatomic molecules, namely H$_2$, LiH, HCl and CO. First nine states belonging to a maximum of $n, \ell =2$ are computed with good accuracy, along with nine other h…

f-oscillators deformation for Moyal algebras

Using general construction of star-product the q-deformed Wigner-Weyl-Moyal quantization procedure is elaborated. The q-deformed Groenewold kernel determining the product of quantum observables is given in explicit form for small nonlinearities corresponding to nonlinear vibrations of classical and quantum q-oscillators. The deformations of Groenewold kernel related to general kinds of nonlinear vibrations described by f-oscillators are considered.

基于彭宁囚禁离子的量子振动振子用于旋转测量的理论研究

Theoretical study on rotation measurement with a quantum vibration oscillator based on Penning trapped ions

本文提出基于彭宁囚禁钙离子晶体的量子谐振子旋转测量方案，利用科里奥利力耦合磁控管运动与轴向振动，通过自旋-运动纠缠探测质心位移，并给出参数匹配条件与灵敏度分析。

Comment on "The Rotation-Vibration Spectrum of Diatomic Molecules with the Tietz-Hua Rotating Oscillator"

We present arguments demonstrating that the application of the Nikiforov-Uvarov polynomial method to solve the Schrödinger equation with the Tietz-Hua potential is valid only when $e^{-b_{h}r_{e}}\leq c_{h}<1$ and $r_{0}<r<+\infty $. In particular, it is pointed out that the numerical results with $c_{h}\neq 0$ for the diatomic molecules $\mathrm{HF}$, $\mathrm{N}_{2}$, $\mathrm{I}_{2}$, $\mathrm{H}_{2}$, $\mathrm{O}_{2}$ and $\mathrm{O}_{2}^{+}$ given in Tables 3-5 by Hamzavi and co-workers are wrong. When $-1\leq c_{h}<0$ or $0<c_{h}<e^{-b_{h}r_{e}}$, this approach is not suitable. In both c…

超长程 Cs-RbCs Rydberg 分子：偶极矩的非绝热性

Ultralong-range Cs-RbCs Rydberg molecules: non-adiabaticity of dipole moments

该研究考察 Cs-RbCs 超长程多原子 Rydberg 分子，分析电荷–偶极相互作用导致的非绝热耦合及其对光镊中分子形成概率和振动态衰减干涉特征的影响。

基于混合量子干涉仪的抗粒子损失鲁棒相位计量

Robust phase metrology with hybrid quantum interferometers against particle losses

提出自旋-振子混合量子干涉仪，通过解纠缠操作将参数信息转移至自旋自由度，实现对粒子损失鲁棒的高精度相位测量，超越标准量子极限。

Strong negative nonlinear friction from induced two-phonon processes in vibrational systems

Self-sustained vibrations in systems ranging from lasers to clocks to biological systems are often associated with the coefficient of linear friction, which relates the friction force to the velocity, becoming negative [1,2]. The runaway of the vibration amplitude is prevented by positive nonlinear friction that increases rapidly with the amplitude. Here we use a modulated electromechanical resonator to show that nonlinear friction can be made negative and sufficiently strong to overcome positive linear friction at large vibration amplitudes. The experiment involves applying a drive that simul…

量子参量振荡器中共振力诱导的对称性破缺

Resonant-force induced symmetry breaking in a quantum parametric oscillator

本研究探讨量子参量振荡器中共振力诱导的对称性破缺，揭示力与热浴耦合量子涨落的相互作用可使效应极强，态数多时切换速率会出现指数级因子，并分析了预分岔等极限情形下的该因子。

Many-body theory of positron binding in polyatomic molecules

Positrons bind to molecules leading to vibrational excitation and spectacularly enhanced annihilation. Whilst positron binding energies have been measured via resonant annihilation spectra for $\sim$90 molecules in the past two decades, an accurate \emph{ab initio} theoretical description has remained elusive. Of the molecules studied experimentally, calculations exist for only 6, and for these, standard quantum chemistry approaches have proved severely deficient, agreeing with experiment to at best 25% accuracy for polar molecules, and failing to predict binding in nonpolar molecules. The mec…

Preparation and decay of a single quantum of vibration at ambient conditions

A single quantum of excitation of a mechanical oscillator is a textbook example of the principles of quantum physics. Mechanical oscillators, despite their pervasive presence in nature and modern technology, do not generically exist in an excited Fock state. In the past few years, careful isolation of GHz-frequency nano-scale oscillators has allowed experimenters to prepare such states at milli-Kelvin temperatures. These developments illustrate the tension between the basic predictions of quantum mechanics that should apply to all mechanical oscillators existing even at ambient conditions, and…

Sympathetic cooling of a membrane oscillator in a hybrid mechanical-atomic system

Sympathetic cooling with ultracold atoms and atomic ions enables ultralow temperatures in systems where direct laser or evaporative cooling is not possible. It has so far been limited to the cooling of other microscopic particles, with masses up to $90$ times larger than that of the coolant atom. Here we use ultracold atoms to sympathetically cool the vibrations of a Si$_3$N$_4$ nanomembrane, whose mass exceeds that of the atomic ensemble by a factor of $10^{10}$. The coupling of atomic and membrane vibrations is mediated by laser light over a macroscopic distance and enhanced by placing the m…

快速旋转的C60富勒烯中的遍历性破缺

Ergodicity breaking in rapidly rotating C60 fullerenes

本研究在快速旋转的C60富勒烯中首次观测到转动遍历性破缺，发现随角动量增加存在多次遍历与非遍历转变，且低于振动阈值，凸显了富勒烯在介观量子系统中的独特动力学。

AcOCH₃⁺离子的振转结构和电偶极矩

Rovibrational structure and electric dipole moments of the AcOCH$_3$+ ion

研究AcOCH₃⁺对称顶部分子的最低振转态光谱，采用相对论耦合簇方法计算电子结构，结合耦合通道技术获得振转波函数，计算振动态频率和电偶极矩。