Related papers: Quantum state engineering in a five-state chainwis…
The goal in quantum state transfer is to avoid the need to physically transport carriers of quantum information. This is achieved by using a suitably engineered Hamiltonian that induces the transfer of the state of one subsystem to another.…
We investigate the usefulness of a recently introduced five qubit state by Brown $\it et al. \normalfont$ \cite{Brown} for quantum teleportation, quantum state sharing and superdense coding. It is shown that this five-qubit state can be…
Defining a computational basis of pseudo-number states, we interpret a coherent state of large amplitude, $|\alpha|\gg\frac{d}{2\pi}$, as a qudit --- a $d$-level quantum system --- in a state that is an even superposition of $d$…
Adiabatic process has found many important applications in modern physics, the distinct merit of which is that it does not need accurate control over the timing of the process. However, it is a slow process, which limits the application in…
We propose two schemes to coherently transfer arbitrary quantum states of the two-electron singlet-triplet qubit across a chain of 3 quantum dots. The schemes are based on electrical control over the detuning energy of the quantum dots. The…
We propose an efficient strategy to find optimal control functions for state-to-state quantum control problems. Our procedure first chooses an input state trajectory, that can realize the desired transformation by adiabatic variation of the…
Within the Franck-Condon approximation, the single ionization of H$_2$ leaves H$_2^+$ in a coherent superposition of 19 nuclear vibrational states. We numerically design an optimal laser pulse train to transfer such a coherent nuclear wave…
When studying the perfect transfer of a quantum state from one site to another, it is typically assumed that one can receive the arriving state at a specific instant in time, with perfect accuracy. Here, we study how sensitive perfect state…
The transfer of quantum entanglement (or quantum coherence) is not only fundamental in quantum mechanics but also important in quantum information processing. We here propose a way to achieve the coherent transfer of $W$-class entangled…
We propose a scheme to prepare arbitrary superpositions of quantum states in double quantum--dots irradiated by coherent microwave pulses. Solving the equations of motion for the dot density matrix, we find that dephasing rates for such…
We consider the problem of bi-directional controlled quantum teleportation of information encoded in phase opposite coherent state among two distant partners Alice and Bob, with the consent of controller, Charlie. We use five-mode…
We propose a strategy for perfect state transfer in spin chains based on the use of an unmodulated coupling Hamiltonian whose coefficients are explicitly time dependent. We show that, if specific and non-demanding conditions are satisfied…
We suggest a protocol for perfect quantum communication through spin chain channels. By combining a dual-rail encoding with measurements only at the receiving end, we can get conclusively perfect state transfer, whose probability of success…
In this paper, we investigate the quantum transfer for the system with three-level $\Lambda$-type structure, and construct a shortcut to the adiabatic passage via picture transformation to speed up the evolution. We can design the pulses…
Photon-echo based optical quantum memory schemes often employ intermediate steps to transform optical coherences to spin coherences for longer storage times. We analyze a scheme that uses three identical chirped control pulses for coherence…
By periodical two-step modulation, we demonstrate that the dynamics of multilevel system can still evolve even in multiple large detunings regime, and provide the effective Hamiltonian (of interest) for this system. We then illustrate this…
Along with the scaling of dimensions in quantum systems, transitions between the system's energy levels would become close in frequency, which are conventionally resolved by weak and lengthy pulses. Here, we extend and experimentally…
We present a scheme to realize multiple-qubit quantum state transfer and quantum logic gate by combining the advantages of Vitanov-style pulses and dressed-state-based shortcut to adiabaticity (STA) in Rydberg atoms. The robustness of the…
Considering a two-level quantum system, we have proposed and represented a new approach for robust population transfer. In this scheme, the laser frequency has been swept in a finite time interval which simplifies the experimental…
Many quantum algorithms can be seen as a transition from a well-defined initial quantum state of a complex quantum system, to an unknown target quantum state, corresponding to a certain eigenvalue either of the Hamiltonian or of a…