0000000000427500
AUTHOR
B. Rousseaux
Arbitrary qudit gates by adiabatic passage
We derive an adiabatic technique that implements the most general SU($d$) transformation in a quantum system of $d$ degenerate states, featuring a qudit. This technique is based on the factorization of the SU($d$) transformation into $d$ generalized quantum Householder reflections, each of which is implemented by a two-shot stimulated Raman adiabatic passage with appropriate static phases. The energy of the lasers needed to synthesize a single Householder reflection is shown to be remarkably constant as a function of $d$. This technique is directly applicable to a linear trapped ion system with $d+1$ ions. We implement the quantum Fourier transform numerically in a qudit with $d=4$ (defined…
Quantum emitter states dressed by the plasmon modes of a metal nanoparticle in the strong coupling regim
The quantum control of emitters is a key issue for quantum information processing at the nanoscale. This generally necessitates the strong coupling of emitters to a high Q-cavity for efficient manipulation of the atoms and field dynamics (cavity quantum electrodynamics or cQED). Since almost a decade, strong efforts are put to transpose cQED concepts to plasmonics in order to profit of the strong mode confinement of surface plasmons polaritons. Despite the intrinsic presence of lossy channels leading to strong decoherence in plasmonics systems, it has been experimentally proven that it is possible to reach the strong coupling regim [1].
Quantum plasmonics with multi-emitters: application to stimulated Raman adiabatic passage
We construct a mode-selective effective model describing the interaction of the localised surface plasmon polaritons (LSPs) supported by a spherical metal nanoparticle (MNP) with N quantum emitters (QEs) in an arbitrary geometric arrangement. Simplifying previously presented procedures, we develop a formulation in which the field response in the presence of the MNP can be decomposed into orthogonal modes, expanding the Green tensor of the system in the spherical vector harmonics basis and using the generalized global Löwdin orthogonalization algorithm. We investigate the possibility of using the LSPs as mediators of an efficient control of population transfer between two QEs. We show that a…
Dressed states of a quantum emitter strongly coupled to a metal nanoparticle
Hybrid molecule-plasmonic nanostructures have demonstrated their potential for surface enhanced spectroscopies, sensing, or quantum control at the nanoscale. In this Letter, we investigate the strong coupling regime and explicitly describe the hybridization between the localized plasmons of a metal nanoparticle and the excited state of a quantum emitter, offering a simple and precise understanding of the energy exchange in full analogy with cavity quantum electrodynamics treatment and a dressed atom picture. Both near-field emission and far-field radiation are discussed, revealing the richness of such optical nanosources.