Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userCorrelated Quantum Memory: Manipulating Atomic Entanglement via Electromagnetically Induced Transparency
62
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
We propose a feasible scheme of quantum state storage and manipulation via electromagnetically induced transparency (EIT) in flexibly $united$ multi-ensembles of three-level atoms. For different atomic array configurations, one can properly steer the signal and the control lights to generate different forms of atomic entanglement within the framework of linear optics. These results shed new light on designing the versatile quantum memory devices by using, e.g., an atomic grid.
rate research
Read More
We investigate a hybrid optomechanical system comprised of a mechanical oscillator and an atomic 3-level ensemble within an optical cavity. We show that a suitably tailored cavity field response via Electromagnetically Induced Transparency (EIT) in the atomic medium allows for strong coupling of the mechanical mirror oscillations to the collective atomic ground-state spin. This facilitates ground-state cooling of the mirror motion, quantum state mapping and robust atom-mirror entanglement even for cavity widths larger than the mechanical oscillator frequency.
We provide a broad outline of the requirements that should be met by components produced for a Quantum Information Technology (QIT) industry, and we identify electromagnetically induced transparency (EIT) as potentially key enabling science toward the goal of providing widely available few-qubit quantum information processing within the next decade. As a concrete example, we build on earlier work and discuss the implementation of a two-photon controlled phase gate and a one-photon phase gate using the approximate Kerr nonlinearity provided by EIT. We rigorously the dependence of the performance of these gates on atomic dephasing and field detuning and intensity, and we calculate the optimum parameters needed to apply a pi phase shift in a gate of a given fidelity. Although high-fidelity gate operation will be difficult to achieve with realistic system dephasing rates, the moderate fidelities that we believe will be needed for few-qubit QIT seem much more obtainable.
We discuss continuous observation of the momentum of a single atom by employing the high velocity sensitivity of the index of refraction in a driven $Lambda$-system based on electromagnetically induced transparency (EIT). In the ideal limit of unit collection efficiency this provides a quantum limited measurement with minimal backaction on the atomic motion. A feedback loop, which drives the atom with a force proportional to measured signal, provides a cooling mechanism for the atomic motion. We derive the master equation which describes the feedback cooling and show that in the Lamb-Dicke limit the steady state energies are close to the ground state, limited only by the photon collection efficiency. Outside of the Lamb-Dicke regime the predicted temperatures are well below the Doppler limit.
We demonstrate experimentally the delay of squeezed light and entanglement using Electromagnetically Induced Transparency (EIT) in a rubidium vapour cell. We perform quadrature amplitude measurements of the probe field and find no appreciable excess noise from the EIT process. From an input squeezing of 3.1 dB at low sideband frequencies, we observed the survival of 2 dB of squeezing at the EIT output. By splitting the squeezed light on a beam-splitter, we generated biased entanglement between two beams. We transmit one of the entangled beams through the EIT cell and correlate the quantum statistics of this beam with its entangled counterpart. We experimentally observed a 2 $mu$s delay of the biased entanglement and obtained a preserved degree of wavefunction inseparability of 0.71, below the unity value for separable states.
We show that an alkali atom with a tripod electronic structure can yield rich electromagnetically induced transparency phenomena even at room temperature. In particular we introduce double-double electromagnetically induced transparency wherein signal and probe fields each have two transparency windows. Their group velocities can be matched in either the first or second pair of transparency windows. Moreover signal and probe fields can each experience coherent gain in the second transparency windows. We explain using a semi-classical-dressed-picture to connect the tripod electronic structure to a double-Lambda scheme.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
