Related papers: Ramsey Interference in a Multi-level Quantum Syste…
The orbital, spin and valley degrees of freedom in silicon quantum dots support many modes of spin qubit operation. However, it is generally challenging to obtain information about the energy level spectrum over large ranges of parameter…
High spin magnetic molecules are promising candidates for quantum information processing because they intrinsically have multiple sublevels for information storage and computational operations. However, due to their susceptibility to the…
We implement a simple feedback mechanism on a two-mode cavity QED system to preserve the Zeeman coherence of a ground state superposition that generates quantum beats on the second-order correlation function. Our investigation includes…
The interaction of a weak probe laser with an inverted-Y type four-level atomic system driven by two additional coherent fields is investigated theoretically. Under the influence of the coherent coupling fields, the steady-state linear…
We examine the propagation of a weak probe light through a coherently driven $Y$-type system. Under the condition that the excited atomic levels decay via same vacuum modes, the effects of quantum interference in decay channels are…
Rotational levels of molecular free radicals can be tuned to degeneracy using laboratory-scale magnetic fields. Because of their intrinsically narrow width, these level crossings of opposite-parity states have been proposed for use in the…
We propose a general approach of protecting a two-level system against decoherence via quantum engineering of non-classical multiple superpositions of coherent states in a non-Markovian reservoir. The scheme surprisingly only uses the…
We determine the late-time dynamics of a generic spin ensemble with inhomogeneous broadening - equivalently, qubits with arbitrary Zeeman splittings - coupled to a dissipative environment with strength decreasing as $1/t$. The approach to…
We study the suppression of noise-induced phase decoherence in a single atomic qubit by employing pulse sequences. The atomic qubit is composed of a single neutral atom in a far-detuned optical dipole trap and the phase decoherence may…
Excitonic transitions offer a possible route to ultrafast optical spin manipulation in coupled nanostructures. We perform here a detailed study of the three principal exciton-mediated decoherence channels for optically-controlled electron…
We analyze how light-induced coherent population oscillations and ground-state Zeeman coherence in an atomic medium with degenerate two-level transitions can modify spectra of applied cw resonant radiation at the sub-mW power level. The use…
Extending quantum control to increasingly complex systems is crucial for both advancing quantum technologies and fundamental physics. In trapped ion systems, quantum logic techniques that combine a well-controlled logic species with a more…
We evaluate the performance and phase diffusion of trapped $^{87}$Rb atoms in an atom-chip sensor with Ramsey interferometry and Hahn's spin echo in the time and phase domains. We trace out how the phase uncertainty of interference fringes…
We explore the possibility to entangle an excitonic two-level system in a semiconductor quantum dot (QD) with a cavity defined on a photonic crystal by sweeping the cavity frequency across its resonance with the exciton transition. The…
We study the quantum dynamics of multiple two-level atoms (qubits) in a waveguide quantum electrodynamics system, with a focus on modified superradiance effects between two or four atoms with finite delay times. Using a numerically exact…
Implications of field quantization on Ramsey interferometry are discussed and general conditions for the occurrence of interference are obtained. Interferences do not occur if the fields in two Ramsey zones have precise number of photons.…
We consider a pair of three-level atoms interacting with the vacuum. The process of disentanglement due to spontaneous emission and the role of quantum interference between principal transitions in this process, are analysed. We show that…
The recent anomalous segregation experiment of Lewandowski et al. (PRL, 88, 070403, 2002) shows dramatic, rapid internal state segregation for two hyperfine levels of rubidium. We simulate an effective one dimensional model of the system…
Motivated by its relation to an $\cal{NP}$-hard problem, we analyze the ground state properties of anti-ferromagnetic Ising-spin networks embedded on planar cubic lattices, under the action of homogeneous transverse and longitudinal…
A strong phase modulated coupling field leads to an amplitude modulation of a probe field in an electromagnetically induced transparency process. Time vs. detuning plots for different modulation frequencies reveals a transition between an…