Journal of Physics B Atomic Molecular and Optical Physics

Effect of dephasing on single-qubit rotation gates

Youssouf Hamidou Issoufa, Azeddine Messikh

Published Oct 22, 2010• 5 citations

Abstract

In this paper we investigate the effect of dephasing on the performance of the quantum rotation gate implemented by adiabatic passage and static laser pulses proposed in Lacour et al (2006 Opt. Commun. 264 362). We show that in an open system, where the three-level lambda system is subjected to dephasing of its ground states, the dephasing will introduce additional dynamic phases which cannot be recompensated as in the closed system. We analyse the evolution of the population by using the quantum jump approach. The results are obtained assuming realistic dephasing rates Γ0 1

DOI: 10.1088/0953-4075/43/21/215506

Related papers

Generalized quantum rotation gates using STIRAP

Youssouf Hamidou Issoufa, Azeddine Messikh, Mohamed Ridza Wahiddin +2 more

In this paper we focus on the generalized quantum rotation gates in the presence of dephasing. We follow the model proposed by Lacour et. al. [1] and extend their technique by applying the quantum jump approach. This approach clearly illustrates the acquired phases which cannot be recompensated and leads to imperfect gates. Numerical solutions for these phases were obtained assuming realistic dephasing rates.

International Conference on Information and Communication Technology for the Muslim World (ICT4M)Mar 1, 20131 citation

Rotation Gates with Controlled Adiabatic Evolutions in Open Systems

Abderrahim Benmachiche, Derradji Bahloul, Gharib S. Mahmoud +1 more

Single quantum rotation gates can be perfectly implemented in a closed system using the controlled adiabatic evolutions process proposed by Itay Hen that may lead to build some quantum circuit blocks [Phys. Rev. A, 022309 (2015)]. These adiabatic evolutions yield to vanishing geometric phases. In this work, we extended Itay’s work by considering a more realistic model where the qubits are subjected to decoherence effects during the adiabatic evolution process. We demonstrate that, in the case of an open system, the decoherence leads to nonvanishing geometric phases and drastically reduces the performance of the quantum rotation gates bellow the fidelity target (0.999).

Open Systems & Information DynamicsSep 1, 20182 citations

The effect of dephasing on superadiabatic single-qubit rotation gates

Gharib S. Mahmoud, Azeddine Messikh

To implement quantum gates stimulated Raman adiabatic passage (STIRAP) can be used. This STIRAP requires high Rabi frequencies and to overcome this problem we use superadiabatic approach. Our model is a tripod consisting of four-level system driven by three resonant fields. These fields are modulated by Gaussian pulses with different amplitudes, phases and time delays. We investigate the robustness of our model against dephasing which are caused by collisions or phase fluctuations of the fields.

Journal of Physics Conference SeriesDec 1, 20170 citations

Single-qubit Rotation Gate Using Three-level Lambda Systems

Youssouf Hamidou Issoufa, Azeddine Messikh

In this paper we investigate the effect of time separation and delay between two f-STIRAP on single-qubit rotation gate based on Lacour et al (2006 Opt. Commun. 264 362). The f-STIRAP is a basic method used to adiabatically transfer population between lower states, where the two pulses terminate simultaneously while maintaining a constant ratio of amplitudes. Furthermore, we obtain numerically the optimal values for the time separation and delay for a perfect single-qubit rotation gate.

Jan 1, 20110 citations

Implementation of one-qubit holonomic rotation gate by adiabatic passage

Rahim Naderali, M. Amniat-Talab, M. Saadati-Niari +1 more

We propose a robust scheme, using tripod stimulated Raman adiabatic passage, to generate one-qubit rotation gate. In this scheme, a four-level atom interacts with three resonant laser pulses and time evolution of the corresponding coherent system is designed such that the rotation gate is implemented at the end of process. Rotation angle in this gate is holonomic and has a geometrical basis in the parameter space. We also explore the effect of spontaneous emission on the population transfer with numerical solution of Schrödinger and Liouville equations.

Jun 1, 20100 citations

Suppression of dephasing and decoherence in open quantum systems

David Bartram

In this thesis, we discuss the possibilities for suppression of decoherence, the loss of purity in an open quantum system, and the related process of dephasing. In the first chapter, we review the literature on the subject of open system dynamics, decoherence and methods of decoherence suppression. In the second chapter, we focus on the specific case of a rotationally hot diatomic molecule as an example of an open quantum system, where molecular vibrational wavepackets are subject to dephasing due to rovibrational coupling. We report analytical and numerical results addressing whether the dephasing rate can be controlled by adjustment of the initial wavepacket phases. It appears that over long timescales, phase-only control is not possible, but for earlier timescales the possibility of phase-only control of dephasing remains. In addition, we point out that the time-dependence of the dephasing process depends significantly upon the degeneracy of the rotational environment states. In the final chapter, we discuss the same system, but apply a qualitatively different method of dephasing suppression based on the nonlinear resonance effect in a driving field. We extend previous work on the topic (Shapiro et al. [1]) by considering the effect of using a train of laser pulses as the driving field, in place of a two-colour continuous-wave laser field. We demonstrate that the pulse train method can be more effective at suppressing dephasing than the two-colour CW case.

Dec 1, 20100 citations