Electromagnetically Induced Transparency in a Double Well Atomic Josephson Junction (original) (raw)

Josephson spectroscopy of a dilute Bose-Einstein condensate in a double-well potential

Physical Review A, 2002

The dynamics of a Bose-Einstein condensate in a doublewell potential are analysed in terms of transitions between energy eigenstates. By solving the time-dependent and timeindependent Gross-Pitaevskii equation in one dimension, we identify tunnelling resonances associated with level crossings, and determine the critical velocity that characterises the resonance. We test the validity of a non-linear two-state model, and show that for the experimentally interesting case, where the critical velocity is large, the influence of higher-lying states is important.

Electromagnetically induced transparency in a Bose–Einstein condensate

We report on the direct observation of the electromagnetically induced transparency (EIT) lineshape of cold 87Rb atoms above and below the transition temperature for Bose–Einstein condensation (BEC). Similar results are observed in both temperature regimes, with an absorption reduction of about 60%. Good agreement with a theoretical model is discussed.

Josephson Junction Arrays with Bose-Einstein Condensates

Science, 2001

We report on the direct observation of an oscillating atomic current in a one-dimensional array of Josephson junctions realized with an atomic Bose-Einstein condensate. The array is created by a laser standing-wave, with the condensates trapped in the valleys of the periodic potential and weakly coupled by the inter-well barriers. The coherence of multiple tunneling between adjacent wells is continuously probed by atomic interference. The square of the small-amplitude oscillation frequency is proportional to the microscopic tunneling rate of each condensate through the barriers, and provides a direct measurement of the Josephson critical current as a function of the intermediate barrier heights. Our superfluid array may allow investigation of phenomena so far inaccessible to superconducting Josephson junctions and lays a bridge between the condensate dynamics and the physics of discrete nonlinear media.

Realization of a single Josephson junction for Bose–Einstein condensates

Applied Physics B, 2005

We report on the realization of a doublewell potential for Rubidium-87 Bose-Einstein condensates. The experimental setup allows the investigation of two different dynamical phenomena known for this system-Josephson oscillations and self-trapping. We give a detailed discussion of the experimental setup and the methods used for calibrating the relevant parameters. We compare our experimental findings with the predictions of an extended two-mode model and find quantitative agreement.

Electromagnetically induced transparency with single atoms in a cavity

Nature, 2010

We present a theory of electromagnetically induced transparency in a cold ensemble of strongly interacting Rydberg atoms. Long-range interactions between the atoms constrain the medium to behave as a collection of superatoms, each comprising a blockade volume that can accommodate at most one Rydberg excitation. The propagation of a probe field is affected by its two-photon correlation which, due to low saturation threshold of the superatoms, is strongly damped within the blockade distance. Our model is computationally very efficient and is in quantitative agreement with the results of recent experiment of Pritchard et al. [Phys. Rev. Lett. 105, 193603 (2010)] PACS numbers: 42.50. Gy, 32.80.Ee, Strong dipole-dipole or van der Waals (VdW) interactions between atoms in highly excited Rydberg states [1] constitute the basis for promising quantum information schemes [2] and interesting many-body effects . Many of these studies utilize the dipole blockade mechanism [9-13] which suppresses multiple Rydberg excitations within a certain interaction (blockade) volume. Electromagnetically induced transparency (EIT) can translate the interactions between Rydberg atoms into sizable interactions between single photons .

Analog of Photon-Assisted Tunneling in a Bose-Einstein Condensate

We study many-body tunneling of a small Bose-Einstein condensate in a periodically modulated, tilted double-well potential. Periodic modulation of the trapping potential leads to an analog of photon-assisted tunneling, with distinct signatures of the interparticle interaction visible in the amount of particles transferred from one well to the other. In particular, under experimentally accessible conditions there exist well-developed half-integer Shapiro-like resonances.

Controllable Josephson junction for photon Bose-Einstein condensates

Physical Review Research, 2021

Josephson junctions are the basis for the most sensitive magnetic flux detectors, the definition of the unit volt by the Josephson voltage standard, and superconducting digital and quantum computing. They result from the coupling of two coherent quantum states, as they occur in superconductors, superfluids, atomic Bose-Einstein condensates, and exciton-polariton condensates. In their ground state, Josephson junctions are characterised by an intrinsic phase jump. Controlling this phase jump is fundamental for applications in computing. Here, we experimentally demonstrate controllable phase relations between photon Bose-Einstein condensates resulting from particle exchange in a thermo-optically tunable potential landscape. Our experiment realises an optical analogue of a controllable 0,π-Josephson junction. By connecting several junctions, we can study a reconfigurable 4-condensate system demonstrating the potential of our approach for analog spin glass simulation. More generally, the combination of static and dynamic nanostructuring techniques introduced in our work offers a powerful platform for the implementation of adaptive optical systems for paraxial light in and outside of thermal equilibrium.

Tunneling electro-conductance of atomic Bose condensates

2008

We consider interaction of an electron with a Bose condensate of atoms having electron affinity. Though states of the electron attached to atoms form a continuous band, tunneling through this band is strongly suppressed by quantum fluctuations of the condensate density. We adapt standard field theory methods originally developed for description of a particle propagating trough a disordered potential and present an exactly soluble analytical model of the process. In contrast with the standard description, we take into account inelastic processes associated with quantum transitions in the condensate. Possibilities of the experimental observation of the phenomenon are discussed.

Electromagnetically Induced Transparency in Quantum Wells

Physica Status Solidi (a), 2002

We show how to compute nonlinear optical absorption spectra of an asymmetric double quantum well in the region of intersubband electronic transitions. The method uses the microscopic calculation of the dephasing due to electron-electron and electron-phonon scattering rates and the macroscopic real density matrix approach to compute the electromagnetic fields and susceptibilities. For a proper choice of the QW widths and of the driving fields we obtain electromagnetically induced transparency. Results are given for GaAs/GaAlAs QWs and experiments are proposed.