Methods for efficient population transfer and quantum logic

The basic technique of stimulated Raman adiabatic passage for laser-induced adiabatic population transfer between discrete quantum states of an asymmetric double quantum well has been used in our study. The results show that the proper time-delay, overlap, and detuning of two pulses allows the coherent transfer between the states of a double quantum well system, leading to the possibility of implementation of semiconductor–based quantum logic gates and high efficiency optical switches. The impact of phase relaxation on the population transfer efficiency is also studied.The basic technique of stimulated Raman adiabatic passage for laser-induced adiabatic population transfer between discrete quantum states of an asymmetric double quantum well has been used in our study. The results show that the proper time-delay, overlap, and detuning of two pulses allows the coherent transfer between the states of a double quantum well system, leading to the possibility of implementation of semiconductor–based quantum logic gates and high efficiency optical switches. The impact of phase relaxation on the population transfer efficiency is also studied.

NANOOct 1, 20090 citations

Quantum computation - alternative models and algorithms

Dorit Aharonov

Sep 12, 20060 citations

Optimal and robust control of population transfer in asymmetric quantum-dot molecules

Yu 裕 Guo 郭, Songshan Ma, Chuan‐Cun Shu

We present an optimal and robust quantum control method for efficient population transfer in asymmetric double quantum-dot molecules. We derive a long-duration control scheme that allows for highly efficient population transfer by accurately controlling the amplitude of a narrow-bandwidth pulse. To overcome fluctuations in control field parameters, we employ a frequency-domain quantum optimal control theory method to optimize the spectral phase of a single pulse with broad bandwidth while preserving the spectral amplitude. It is shown that this spectral-phase-only optimization approach can successfully identify robust and optimal control fields, leading to efficient population transfer to the target state while concurrently suppressing population transfer to undesired states. The method demonstrates resilience to fluctuations in control field parameters, making it a promising approach for reliable and efficient population transfer in practical applications.We present an optimal and robust quantum control method for efficient population transfer in asymmetric double quantum-dot molecules. We derive a long-duration control scheme that allows for highly efficient population transfer by accurately controlling the amplitude of a narrow-bandwidth pulse. To overcome fluctuations in control field parameters, we employ a frequency-domain quantum optimal control theory method to optimize the spectral phase of a single pulse with broad bandwidth while preserving the spectral amplitude. It is shown that this spectral-phase-only optimization approach can successfully identify robust and optimal control fields, leading to efficient population transfer to the target state while concurrently suppressing population transfer to undesired states. The method demonstrates resilience to fluctuations in control field parameters, making it a promising approach for reliable and efficient population transfer in practical applications.

Chinese Physics BOct 24, 20234 citations

Quantum Algorithms and Methods

Ivan B. Djordjević

Elsevier eBooksJan 1, 20212 citations

Quantum computation based on population transfers by rapid adiabatic passages

Wei Li, Hsi‐Sheng Goan, Yueh-Nan Chen

AIP conference proceedingsJan 1, 20080 citations

Robust operation of a universal set of logic gates for quantum computation using adiabatic population transfer between molecular levels

Cian Menzel-Jones, Moshe Shapiro

We present a robust construction of a set of logic gates operating on a system of qubits encoded in the rovibrational eigenstates of an ${\mathrm{Na}}_{2}$ molecule using the optical adiabatic population transfer (APT) phenomenon. We demonstrate the operation of a complete universal gate set for quantum computation on a two-qubit system with gate fidelities approaching 99.99%. Like other APT-based processes, the method is robust against substantial fluctuations in the intensity of the laser pulse. Our construction is easily scalable to deal with a larger number of qubits. With the aid of the set of gates thus shown we may construct pulse sequences for a wide class of quantum logic operations. We also show how to produce a representation of Bell states from a representation of product states with essentially perfect fidelity. Our scheme can be realized in all diatomic and polyatomic molecules that possess easily accessible and well characterized excited electronic states.We present a robust construction of a set of logic gates operating on a system of qubits encoded in the rovibrational eigenstates of an ${\mathrm{Na}}_{2}$ molecule using the optical adiabatic population transfer (APT) phenomenon. We demonstrate the operation of a complete universal gate set for quantum computation on a two-qubit system with gate fidelities approaching 99.99%. Like other APT-based processes, the method is robust against substantial fluctuations in the intensity of the laser pulse. Our construction is easily scalable to deal with a larger number of qubits. With the aid of the set of gates thus shown we may construct pulse sequences for a wide class of quantum logic operations. We also show how to produce a representation of Bell states from a representation of product states with essentially perfect fidelity. Our scheme can be realized in all diatomic and polyatomic molecules that possess easily accessible and well characterized excited electronic states.

Physical Review AMay 7, 200731 citations

We present a robust construction of a set of logic gates operating on a system of qubits encoded in the rovibrational eigenstates of an

{\mathrm{Na}}_{2}

molecule using the optical adiabatic population transfer (APT) phenomenon. We demonstrate the operation of a complete universal gate set for quantum computation on a two-qubit system with gate fidelities approaching 99.99%. Like other APT-based processes, the method is robust against substantial fluctuations in the intensity of the laser pulse. Our construction is easily scalable to deal with a larger number of qubits. With the aid of the set of gates thus shown we may construct pulse sequences for a wide class of quantum logic operations. We also show how to produce a representation of Bell states from a representation of product states with essentially perfect fidelity. Our scheme can be realized in all diatomic and polyatomic molecules that possess easily accessible and well characterized excited electronic states.