Quantum Plasmonic Circuits

Abstract

Interactions between light and matter can be dramatically modified by concentrating light into a small volume for a long period of time. Gaining control over such interaction is critical for realizing many schemes for classical and quantum information processing, including optical and quantum computing, quantum cryptography, and metrology and sensing. Plasmonic structures are capable of confining light to nanometer scales far below the diffraction limit, thereby providing a promising route for strong coupling between light and matter, as well as miniaturization of photonic circuits. At the same time, however, the performance of plasmonic circuits is limited by losses and poor collection efficiency, presenting unique challenges that need to be overcome for quantum plasmonic circuits to become a reality. In this paper, we survey recent progress in controlling emission from quantum emitters using plasmonic structures, as well as efforts to engineer surface plasmon propagation and design plasmonic circuits using these elements.

Efficient unidirectional polarization-controlled excitation of surface plasmon polaritons

“…The developed approach represents also a new way of encoding the polarization information in SPPs, suggesting the efficient method for inter-conversion of polarization-encoded photon qubits and SPPs, a process that is very important in the context of quantum plasmonic circuits. 26 Another interesting development can be to realize complete on-chip characterization of polarization states of light by combining the polarization-controlled SPP coupler, which allows one to excite separate SPPs associated with orthogonal linear polarizations, with a suitable plasmonic interference circuitry 27 to compare their phases and integrated SPP detectors 28 to conduct quantitative analysis of amplitudes of the incident orthogonal linear polarizations as well as their phase difference. Overall, we foresee many exciting developments and applications of the demonstrated approach within plasmonics.…”

Plasmonic circuits for manipulating optical information

“…Importantly, these experiments reveal that the radiative decay of a plasmon excited by a single photon also yields a single photon, even though a surface plasmon is a collective phenomenon consisting of the in-phase oscillations of a large number of electrons [54][55][56][57][58]. Active plasmonic devices including those with gain have been reviewed elsewhere [59]. Gain media consist of materials with electronic states that can be optically excited and subsequently de-excited in phase by another light beam, as occurs in solid-state lasers.…”

“…In particular, the plasmons remain coherent with the incident light, suggesting that it should be possible to observe quantum coherence effects with them or to use plasmons for manipulating quantum properties of light. The resurgence of interest in plasmonics has been accompanied by an interest in their quantum properties [59,209], which includes coherence, entanglement, and wave-particle duality [209]. Plasmon waveguides have been used to observe quantum interference [65] as well as two plasmon quantum interference [210].…”

Single-molecule controlled emission in planar plasmonic cavities

“…11 Moreover, the integration of an efficient singlephoton source into a photonic device is a challenging topic and plasmonic-based elements appear promising in this context thanks to the strong mode confinement. [12][13][14] In this work, we are interested in the control of single-emitter fluorescence in coplanar plasmonic cavities.…”