We design, by invariant-based inverse engineering, resonant laser pulses to perform fast population transfers in three-level systems. The laser intensities to improve the fidelity or to achieve a perfect transfer are examined for different protocols. They can be reduced by populating the intermediate state and by multimode driving.
Abstract We propose a scheme to inverse engineer the Hamiltonian of any general driven three-level system by employing a SU(3) transformation. For special cases, the scheme is then introduced to explore nonadiabatic dynamic evolution of systems with two-photon resonance. We demonstrate that, by selecting the control parameters with explicit function forms, both the ideal process and the practical evolution driving with the truncation of pulses, systematic error and decaying can implement fast population transfer with high fidelity. Moreover, the nonadiabatic passages are not reconstructed by the superadiabatic approach.
Enhanced population transfer from the lowest to the highest level in the three-state ladder 5s\ensuremath{\rightarrow}5p\ensuremath{\rightarrow}5d of the rubidium atom by frequency-swept ultrashort laser pulses is observed if the frequency sweep first makes the pulse resonant with the 5s\ensuremath{\rightarrow}5p transition, and later with the 5p\ensuremath{\rightarrow}5d transition. With this ``intuitive'' scheme it is possible to achive complete population inversion via the intermediate level by two successive adiabatic passages. Complete inversion is also obtained by a ``counterintuitive'' direction of the frequency sweep, in which case population of the intermediate level during the pulse is strongly reduced.
Nuclear coherent population transfer (NCPT) plays an important role in the exploration and application of atomic nuclei. How to achieve high-fidelity NCPT remains so far challenging. Here, we investigate the complete population transfer of nuclear states. We first consider a cyclic three-level system, based on the mixed-state inverse engineering scheme by adding additional laser fields in an open three-level nuclear system with spontaneous emission. We find the amplitude of the additional field is related to the ratio of the pump and Stokes field amplitudes. As long as an appropriate additional field is selected, complete transfer can be achieved even when the intensities of the pump and Stokes fields are exceedingly low. The transfer efficiency exhibits excellent robustness with respect to laser peak intensity and pulse delay. We demonstrate the effectiveness through examples such as 229Th,223Ra,113Cd, and 97Tc, which have a long lifetime excited state, as well as 187Re,172Yb,168Er, and 154Gd with a short lifetime excited state. Focusing on the case without additional coupling, we further reduce the three-level system to an effective two-level problem. We modify the pump and Stokes pulses by using counterdiabatic driving to implement high-fidelity population transfer. The schemes open up new possibilities for controlling nuclear states.
We propose an alternative scheme for constructing a shortcut to implement the quantum state transfer between two three-level atoms founded on the invariant-based inverse engineering in a cavity quantum electronic dynamics (QED) system. Quantum information can be quickly transferred between atoms by taking advantage of the cavity field as a medium. Through our design of the time-dependent laser pulse and atom–cavity coupling, we send atoms through the cavity within a short time interval, which involves the two processes of the invariant dynamics between each atom and the cavity field simultaneously. We redesign a reasonable Gaussian-type wave form in the atom–cavity coupling for a realistic experimental operation. Numerical simulation shows that the target state can be quickly populated with a high fidelity which is robust against both the parameter fluctuations and the dissipation.
Shortcuts to adiabaticity in various quantum systems have attracted much attention with their wide applications in quantum information processing and quantum control. In this paper, we concentrate on a stimulated Raman shortcut-to-adiabatic passage in quantum three-level systems. To implement counterdiabatic driving but without additional coupling, we first reduce the quantum three-level systems to effective two-level problems at large intermediate-level detuning, or on resonance, apply counterdiabatic driving along with the unitary transformation and eventually modify the pump and Stokes pulses for achieving fast and high-fidelity population transfer. The required laser intensity and stability against parameter variation are further discussed, to demonstrate the advantage of shortcuts to adiabaticity.
We introduce a reverse-engineered scheme for achieving the precise control of population transfer in nonlinear quantum systems characterized by a 1:2 resonance. This scheme involves the use of two resonant laser pulses that transition from initial and final states to an intermediate level exhibiting irreversible losses. In comparison to alternative techniques, our approach offers computational efficiency advantages. Notably, the analytically defined form of the pump pulse enables tailored control strategies, enhancing robustness against decoherence and imperfections. This flexibility extends to choosing dump pulses and designing time evolution scenarios. These features open doors for practical implementation and scalability in quantum technologies, with potential applications in quantum information processing, quantum computing, and quantum communication.