Electromagnetically induced transparency is a promising approach to implement quantumcommunication in quantum system. In this study, quantum coherence and interference in theexcitation pathways of a three-level Λ atomic system leads to the formation of new states of matter(i.e. the dark state). This state decouples itself from the excitation beams leading to phenomenasuch as coherent population trapping (CPT), electromagnetically induced transparency (EIT).Taking into account quantum coherence and interference in an optically dense electromagneticallyinducedtransparent medium, we investigate the non-destructive storage and retrieval of singlephotonquantum states in the dark state of this dense ensemble of gas phase medium. The storageand retrieval process is based on the intracavity electromagnetically induced transparency by whichproperties of a cavity filled with three-level Λ-type atoms are manipulated by an external control field.We demonstrate the peculiar case for the storage and retrieval of time-entangled periodic input pulses(a soliton train) in the dark state by adiabatic photon transfer under conditions of dynamicalimpedance matching. These multiplexed photon states are expected to allow sharing quantuminformation among many users, and are currently of very high demand for applications in longdistanceand multiplexed quantum communication.
Electromagnetically induced transparency is a promising approach to implement quantumcommunication in quantum system. In this study, quantum coherence and interference in theexcitation pathways of a three-level Λ atomic system leads to the formation of new states of matter(i.e. the dark state). This state decouples itself from the excitation beams leading to phenomenasuch as coherent population trapping (CPT), electromagnetically induced transparency (EIT).Taking into account quantum coherence and interference in an optically dense electromagneticallyinducedtransparent medium, we investigate the non-destructive storage and retrieval of singlephotonquantum states in the dark state of this dense ensemble of gas phase medium. The storageand retrieval process is based on the intracavity electromagnetically induced transparency by whichproperties of a cavity filled with three-level Λ-type atoms are manipulated by an external control field.We demonstrate the peculiar case for the storage and retrieval of time-entangled periodic input pulses(a soliton train) in the dark state by adiabatic photon transfer under conditions of dynamicalimpedance matching. These multiplexed photon states are expected to allow sharing quantuminformation among many users, and are currently of very high demand for applications in longdistanceand multiplexed quantum communication.
Electromagnetically induced transparency is a promising approach to implement quantumcommunication in quantum system. In this study, quantum coherence and interference in theexcitation pathways of a three-level Λ atomic system leads to the formation of new states of matter(i.e. the dark state). This state decouples itself from the excitation beams leading to phenomenasuch as coherent population trapping (CPT), electromagnetically induced transparency (EIT).Taking into account quantum coherence and interference in an optically dense electromagneticallyinducedtransparent medium, we investigate the non-destructive storage and retrieval of singlephotonquantum states in the dark state of this dense ensemble of gas phase medium. The storageand retrieval process is based on the intracavity electromagnetically induced transparency by whichproperties of a cavity filled with three-level Λ-type atoms are manipulated by an external control field.We demonstrate the peculiar case for the storage and retrieval of time-entangled periodic input pulses(a soliton train) in the dark state by adiabatic photon transfer under conditions of dynamicalimpedance matching. These multiplexed photon states are expected to allow sharing quantuminformation among many users, and are currently of very high demand for applications in longdistanceand multiplexed quantum communication.
Quantum coherence and interference in atomic systems can lead to interesting optical phenomena such as nonabsorbing resonances, lasing without inversion, generating an ultrahigh index of refraction without absorption, propagation of light pulses without losses. In the last-named is given the title transparency. Up to now it is known some types of transparency in multi-level resonant media. One of them is electromagnetically induced transparency (EIT). The phenomenon of EIT in the propagation of laser radiation through an absorbing medium has been recently investigated and explained in terms of quantum coherence and interference for multi-level atomic system. For instance in the (Lambda) -system, if the atomic medium is prepared in a quantum superposition of states, matched pulses, i.e., a pair of optical pulses whose amplitude and phase have a well defined relation, propagate without absorption. The mechanism of coherent population trapping is responsible for EIT in a (Lambda) -system. There is another, well known mechanism for creating transparency in a two-state atom: self-induced transparency, or SIT. Here, a single pulse whose area (the integral of its Rabi frequency over time) is 2(pi) is applied to the medium. Such a pulse causes the atoms to cycle smoothly from the ground to the excited state and then back again. In principle, such a pulse can propagate over long distances. SIT can be generalized to multi-level systems and multiple quasi-monochromatic fields. Generalization of SIT in a (Lambda) -system was obtained in reference 2. In this report we present a new type of transparency (combined transparency). This type describes propagation of laser pulse through a (Lambda) -type medium where the initial atomic state is prepared in the form of spatially varying coherent superposition of low-energetic states (initial coherency gradient). The common envelope behaves as usual 2(pi) hyperbolic secant pulse, but the ratio between the components of frequencies transitions 1> yields 3> and 2> yields 3> changes due to coherent Raman scattering so (phi) equals atan(E1/E2) equals (pi) /2-Gz, where z is the coordinate, G is the constant determined by both the incident pulse parameters and the initial coherence between the atomic states. Our solution demonstrates a direct connection of EIT in adiabatic regime to the SIT effects. This type of a transparency is given the title screw-type transparency, because for the given form of incident pulse (pitch of screw) medium is transparent, if medium's the initial coherence gradient is correspondingly prepared (thread on a engine nut). Besides a transparency, this phenomenon contains a transformation of the incident pulse frequency during the process of the propagation. This property of the phenomena can be result in a complete conversion of the frequency.
Quantum networks will enable extraordinary capabilities for communicating and processing quantum information. These networks require a reliable means of storage, retrieval, and manipulation of quantum states at the network nodes. A node receives one or more coherent inputs and sends a conditional output to the next cascaded node in the network through a quantum channel. Here, we demonstrate this basic functionality by using the quantum interference mechanism of electromagnetically induced transparency in a transmon qubit coupled to a superconducting resonator. First, we apply a microwave bias, i.e., drive, to the qubit-cavity system to prepare a Λ-type three-level system of polariton states. Second, we input two interchangeable microwave signals, i.e., a probe tone and a control tone, and observe that transmission of the probe tone is conditional upon the presence of the control tone that switches the state of the device with up to 99.73% transmission extinction. Importantly, our electromagnetically induced transparency scheme uses all dipole allowed transitions. We infer high dark state preparation fidelities of >99.39% and negative group velocities of up to -0.52±0.09 km/s based on our data.
Electromagnetically induced transparency (EIT) is well known as a quantum optical phenomenon that permits a normally opaque medium to become transparent due to the quantum interference between transition pathways. This work addresses multi-soliton dynamics in an EIT system modeled by the integrable Maxwell–Bloch (MB) equations for a three-level Λ-type atomic configuration. By employing a generalized gauge transformation, we systematically construct explicit N-soliton solutions from the corresponding Lax pair. Explicit forms of one-, two-, three-, and four-soliton solutions are derived and analyzed. The resulting pulse structures reveal various nonlinear phenomena, such as temporal asymmetry, energy trapping, and soliton interactions. They also highlight coherent propagation, elastic collisions, and partial storage of pulses, which have potential implications for the design of quantum memory, slow light, and photonic data transport in EIT media. In addition, the conservation of fundamental physical quantities, such as the excitation norm and Hamiltonian, is used to provide direct evidence of the integrability and stability of the constructed soliton solutions.
The quantum coherence phenomenon of electromagnetically induced transparency (EIT) is observed in a three-level system composed of an excited state and two coherent superpositions of the two ground-state levels. This peculiar ground state basis is composed of the so-called bright and dark states of the same atomic system in a standard coherent population trapping configuration. The characteristics of EIT, namely, width of the transmission window and reduced group velocity of light, in this unusual basis, are theoretically and experimentally investigated and are shown to be essentially identical to those of standard EIT in the same system.
We theoretically studied the implementation of a quantum memory and an optical transistor in a system composed by a single atom trapped inside a high finesse cavity. In order to store and map the quantum state of an input pulse onto internal states of the single atom (quantum memory) we employ the electromagnetically induced transparency (EIT) phenomenon (which can work out as an optical transistor) where the information can be transferred to the dark state of the atom modelled by a three-level system in a Λ-type configuration. In our model we consider a suitable temporal shape for the control field that ensures the adiabaticity of the storage process and retrieval of the probe pulse. The dynamic of the field inside the cavity was obtained by master equation approach, while the outside field was calculated by input-output formalism. We have analysed two different setups: i) two-sided and ii) single-sided cavities. While the first setup is the most appropriate and commonly used to observe cavity-EIT in the transmission spectrum, thus the best configuration for the optical transistor, the maximum quantum memory efficiency can not reach reasonable values, being limited to 50% for symmetric cavities. On the other hand, with single-sided cavity the quantum memory efficiency increases considerably and can reach values close to 100% in the strong atom-field coupling regime. However this specific setup is not favourable to observe the cavity-EIT effect in the transmission spectrum and then it is not appropriate to control the transmission of light pulses.