Search results for "Rabi cycle"
showing 10 items of 13 documents
Jaynes-Cummings model with atomic position distribution
1995
The position as well as the width of the atomic wave packet passing through an optical cavity may affect the matter-field interaction. As a result, the internal dynamics of a two-level atom, such as the Rabi oscillations or the collapse and revival phenomenon, may be strongly modified with respect to the standard Jaynes-Cummings model. In particular, for a sufficiently large spread of the atomic position, the atomic population inversion displays the characteristic ringing behavior of the Bessel function ${\mathit{J}}_{0}$ differently from the usual full Rabi oscillation.
New Quantum Effects in the Dynamics of a Two-mode Field Coupled to a Two-level Atom
1994
Abstract The dynamics of a degenerate two-mode electromagnetic field coupled to a single two-level atom is investigated both analytically and numerically. New quantum effects are discussed concerning the time dependence of the photon number and of its fluctuations, assuming that at t = 0 one of the modes is coherent and the other is empty. The field dynamics are dominated by oscillatory net exchanges of a large number of photons between the two modes, displaying amplitude decay. Over a longer time scale, revivals and collapses in the field populations take place. The time scales of these phenomena are much larger than those of the atomic Rabi oscillations decay. Moreover, the system attains…
Quantum information processing on spin degrees of freedom in QDs placed in diluted magnetic semiconductor
2006
The spin degrees of freedom in quantum dot (QD) embedded in a diluted magnetic semiconductor (DMS) medium are considered in a model of a qubit and a gate for quantum information processing (QIP). The qubit is defined as a singlet and triplet pair of states of two electrons in a He-type QD in the DMS medium with strongly enhanced gyromagnetic factor. Methods of qubit rotation (Rabi oscillations) as well as two-qubit operations are suggested and analyzed. Moreover, decoherence related to spin waves (magnon-induced dephasing) in this new system (QD in DMS) is studied, and the relevant time-scale is estimated in accordance with preliminary experimental results. (© 2006 WILEY-VCH Verlag GmbH & C…
Quantum Effects in Charged Particle Traps
2009
It is a fundamental feature of quantum mechanics that a group of particles can be in a state described by one common wavefunction which cannot be factored into individual particle wavefunctions; they are then said to be in an entangled state [294-296]. A measurement of the state of a constituent part of the entangled system determines the state of all the others. In a system that is not entangled, the states of the individual particles are determined independently. Ions isolated and trapped in vacuo in electromagnetic fields provide an unparalleled means of realizing long-lived entangled quantum states [297] through the coupling of the normal modes of oscillation in the trap by the long ran…
The non dissipative damping of the Rabi oscillations as a "which-path" information
2005
Rabi oscillations may be viewed as an interference phenomenon due to a coherent superposition of different quantum paths, like in the Young's two-slit experiment. The inclusion of the atomic external variables causes a non dissipative damping of the Rabi oscillations. More generally, the atomic translational dynamics induces damping in the correlation functions which describe non classical behaviors of the field and internal atomic variables, leading to the separability of these two subsystems. We discuss on the possibility of interpreting this intrinsic decoherence as a "which-way" information effect and we apply to this case a quantitative analysis of the complementarity relation as intro…
Dynamical stabilization of spin systems in time-dependent magnetic fields
2011
The quantum dynamics of a spin system subjected to a Rabi magnetic field configuration modified by a weak oscillating field along the Z-axis is investigated. We show that when the Rabi frequency is appropriately matched with the frequency of the perturbative field, the spin system exhibits a dynamical stabilization phenomenon defined as the tendency to occupy a fixed quantum superposition during a finite period of time.
Non-markovian dynamics and spectrum of a moving atom strongly coupled to the field in a damped cavity
1993
Abstract We study the internal dynamics of an atom entering in its excited state in a damped cavity and strongly coupled to the field. We show that the time evolution of its dipole operator is described by a second order Langevin-like equation with time dependent coefficients. We use this equation to investigate the time dependence of the average population inversion and the spectrum of the emitted radiation. We discuss how Rabi oscillations are modified by the motion of the atom and how the spectrum changes from the vacuum Rabi doublet to a more complex structure having new lines, different frequency localizations and modified widths.
Coherent manipulation of three-qubit states in a molecular single-ion magnet
2017
We study the quantum spin dynamics of nearly isotropic Gd3+ ions entrapped in polyoxometalate molecules and diluted in crystals of a diamagnetic Y3+ derivative. The full energy-level spectrum and the orientations of the magnetic anisotropy axes have been determined by means of continuous-wave electron paramagnetic resonance experiments, using X-band (9-10 GHz) cavities and on-chip superconducting waveguides and 1.5-GHz resonators. The results show that seven allowed transitions between the 2S+1 spin states can be separately addressed. Spin coherence T2 and spin-lattice relaxation T1 rates have been measured for each of these transitions in properly oriented single crystals. The results sugg…
Correlations between Rabi oscillations and atomic translational dynamics
1998
We analyze some aspects of the internal and translational dynamics of a two-level atom interacting with a resonant standing wave of an ideal cavity. We show that the cavity vacuum field can split the incoming wave packet of the excited two-level atom into two parts, whose scalar product in the Hilbert space determines the behavior of the Rabi oscillations. The state of the whole system is derived and allows us to study the correlations between the internal and the translational atomic dynamics. We find that these correlations become negligible when the two parts are sufficiently away from each other in the space.
Quantum-state manipulation via quantum nondemolition measurements in a two-dimensional trapped ion
2001
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 …