理论物理通讯：英文版

Quantum Nondemolition Measurement of the Collective Motional Energy of Two Trapped Ions

ZHENGShi-Biao

Published Jan 1, 2002• 0 citations

Abstract

We propose a quantum nondemolition measurement of the collective motional energy of two trapped ions for the first time.It is based on the excitation of the two ions by two lasers with appropriate frequencies and amplitudes.The scheme also provides a new possibility of preparing vibrational Fock states and laser cooling.

Related papers

Quantum Nondemolition Measurement of the Collective Motional Energy of Two Trapped Ions

Zheng Shi-Biao

We propose a quantum nondemolition measurement of the collective motional energy of two trapped ions for the first time. It is based on the excitation of the two ions by two lasers with appropriate frequencies and amplitudes. The scheme also provides a new possibility of preparing vibrational Fock states and laser cooling.

Communications in Theoretical PhysicsApr 15, 20020 citations

Quantum-state manipulation via quantum nondemolition measurements in a two-dimensional trapped ion

Wang Kaige, Sabrina Maniscalco, Anna Napoli +1 more

The quantum nondemolition measurement is applied to a two-dimensional (2D) trapped-ion model in which two laser beams drive the corresponding vibrational motions and are carrier resonant with the two-level system of the ion. The information about the ionic vibrational energy can be detected by the occupation probability of the internal electronic level. The substantial difference of the 2D model from the one-dimensional one is that two orthogonal beams have a fixed phase shift instead of statistical independence. As a result, the atomic Rabi oscillation is involved in the coherent superposition of two sub-Rabi oscillations induced by the corresponding driving beams. This means that, in the bidimensional case, the phase difference between the two laser beams plays the role of an adjustable external parameter which allows us to optimize the measurement scheme itself, in terms of precision and sensitivity. As in the one-dimensional case, our proposal leads to interesting applications as, for example, the cooling and preparation of arbitrary bimodal Fock states. The model can be considered as a cooling method for the trapped ion from the vibrational thermal state to the vacuum state. Due to the coherent superposition of two sub-Rabi oscillations, the Rabi frequency degeneration and offset may occur in this model. This provides the possibility of generating various entangled superposition of Fock states, the pair coherent state, and entangled pair coherent states.

Physical Review AMar 20, 20019 citations

Quantum Nondemolition Measurement of the Motional Energy of a Trapped Atom

R. L. de Matos Filho, W. Vogel

We propose a quantum nondemolition measurement of the motional energy of an atom confined in a trap. The quantum nondemolition coupling arises from the nonlinear vibronic dynamics of the system which is resonantly driven on a weak electronic transition. Applications are considered, such as laser cooling and preparations of nonclassical states of atomic motion. Examples are vibrational number states and quantum superpositions of coherent states undergoing a Kerr-type nonlinear interaction.

Physical Review LettersJun 10, 199682 citations

Preparation of nonclassical states and measurement of the Wigner function for the collective motion of N trapped ions

Zheng Shi-Biao

We propose a scheme for generating nonclassical states for the centre-of-mass vibrational mode of N trapped ions, including superpositions of several coherent states on a circle and Fock states. In the scheme N trapped ions are driven by a laser beam tuned to the carrier. The scheme also provides a new prospect for laser cooling. The scheme can be used to measure the Wigner function of the collective vibrational mode.

Chinese PhysicsOct 26, 200410 citations

Scheme for direct measurement of the Wigner function of a trapped ion in the intermediate-excitation regime

Shi‐Biao Zheng

We propose a scheme to directly measure the Wigner function for the motion of a trapped ion. Unlike the previous scheme [Phys. Rev. Lett. 78, 2547 (1997)], the present scheme works in the intermediate-excitation regime, which may be of experimental importance in view of decoherence. The scheme can also be used to perform a quantum nondemolition measurement of the vibrational energy and prepare motional Schr\"odinger cat states.

Physical Review AApr 25, 20052 citations

Quantum nondemolition measurements of vibrational populations in ionic traps

L. Davidovich, Miguel Orszag, Nicim Zagury

We discuss a simple implementation of a quantum nondemolition measurement of the vibronic state of a trapped ion. This scheme allows the production of Fock states associated to the center-of-mass motion and the determination of the population distribution of the trap levels, and is based on the vibronic level dependence of the frequency of Rabi oscillations between two internal states of the ion, induced by a resonant carrier field. The same scheme can be used to produce a Schr\"odinger-cat-like state after a single interaction between the trapped ion and the carrier pulse, followed by the detection of the ionic internal state. \textcopyright{} 1996 The American Physical Society.

Physical Review ADec 1, 199657 citations