Related papers: Engineering mixed states in a degenerate four-stat…
Following the method of Victor V. Kozlov et al.[PhysRevA. 74. 063829],we inspect the coherence induced by incoherent pump and spontaneous decay process in $\Lambda$ type three-level atomic system with degenerated lower duplicate levels. The…
We explore the possibilities of creating radiatively stable entangled states of two three-level dipole-interacting atoms in a $\Lambda$ configuration by means of laser biharmonic continuous driving or pulses. We propose three schemes for…
The task of learning a quantum circuit to prepare a given mixed state is a fundamental quantum subroutine. We present a variational quantum algorithm (VQA) to learn mixed states which is suitable for near-term hardware. Our algorithm…
We use optimal control theory to show that for a closed $\Lambda$-system where the excited intermediate level decays to the lower levels with a common large rate, the optimal scheme for population transfer between the lower levels is…
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…
We propose a technique to prepare coherent superpositions of two nondegenerate quantum states in a three-state ladder system, driven by two simultaneous fields near resonance with an intermediate state. The technique, of potential…
We have demonstrated that near complete coherence can be achieved in a four level double lambda-like systems using a train of ultra-short optical pulses. The effect of the Doppler broadening has been analyzed and a scheme has been proposed…
A scheme for fine tuning of quantum operations to improve their performance is proposed. A quantum system in $\Lambda$ configuration with two-photon Raman transitions is considered without adiabatic elimination of the excited (intermediate)…
We demonstrate a new four-wave mixing (4WM) geometry based on structured light. By utilizing near-field diffraction through a narrow slit, the pump beam is asymmetrically structured to modify the phase matching condition, generating…
A coherent state of many spins contains quantum entanglement which increases with a decrease in the collective spin value. We present a scheme to engineer this class of pure state based on incoherent spin pumping with a few collective…
We present a novel scheme for coherent manipulation of populations and robust creation of arbitrary coherent superposition of metastable states of a quantum system with lambda configuration of operating energy levels using laser pulses with…
We propose an improved photoassociation scheme to produce ultracold molecules in their vibronic ground state for the generic case where non-adiabatic effects facilitating transfer to deeply bound levels are absent. Formation of molecules is…
A protocol is proposed to generate atomic entangled states in a cavity QED system. It utilizes Raman transitions or stimulated Raman adiabatic passages between two systems to entangle the ground states of two three-state $\Lambda$-type…
Hybrid quantum systems have been developed with various mechanical, optical and microwave harmonic oscillators. The coupling produces a rich library of interactions including two mode squeezing, swapping interactions, back-action evasion…
Squeezed states are a versatile class of quantum states with applications ranging from quantum computing to high-precision detection. We propose a method for generating tunable squeezed states of light with multiple modes encoded in…
High-dimensional entanglement is a valuable resource for quantum communication, and photon pairs entangled in orbital angular momentum are commonly used for encoding high-dimensional quantum states. However, methods for preparation of…
We present a symmetry-projected configuration mixing scheme to describe ground and excited states, with well defined quantum numbers, of the two-dimensional Hubbard model with nearestneighbor hopping and periodic boundary conditions.…
We discuss a model for quantum computing with initially mixed states. Although such a computer is known to be less powerful than a quantum computer operating with pure (entangled) states, it may efficiently solve some problems for which no…
We examine in detail the quantum memory technique for photons in a double $\Lambda$ atomic ensemble in this work. The novel application of the present technique to create two different quantum probe fields as well as entangled states of…
Tensor networks capture large classes of ground states of phases of quantum matter faithfully and efficiently. Their manipulation and contraction has remained a challenge over the years, however. For most of the history, ground state…