All-optical noise spectroscopy of a solid-state spin

Optical Transparency Induced by a Largely Purcell Enhanced Quantum Dot in a Polarization-Degenerate Cavity

“…In recent years, optically active quantum dots have emerged as useful resources for photonic quantum technologies. Quantum dots emit single photons with high brightness and indistinguishability, − which makes them promising as sources of single and entangled photons for photonic quantum computing. − In addition, these dots can be electrically charged with a single electron or a single hole, thereby offering a ground-state spin qubit. − Strongly coupling a quantum dot spin to a photonic cavity could provide an interface between a single photon and a single spin for quantum information processing, , thereby contributing to the ongoing efforts of establishing quantum networks. , Such strong coupling requires a sufficiently high cooperativity between the spin and the cavity, which typically involves the use of high- Q (>10000) cavities. , An ultrahigh cooperativity has been recently achieved between a quantum dot and a high- Q tunable microcavity formed by utilizing the advanced fabrication of convex mirrors . An alternative approach for achieving such high cooperativities utilizes simple nanofabrication tools (e.g., electron beam lithography) to fabricate photonic crystal cavities.…”

Optical transparency induced by a largely Purcell-enhanced quantum dot in a polarization-degenerate cavity

“…Quantum dots emit single photons with high brightness and indistinguishability [1][2][3][4][5][6][7][8], which makes them promising as sources of single and entangled photons for photonic quantum computing [9][10][11][12]. In addition, these dots can be electrically charged with a single electron or a single hole, thereby offering a ground state spin qubit [13][14][15][16][17][18][19]. The coupling of such spins to single photons enables the generation of photon-photon interactions for quantum information processing [20], and could contribute to the ongoing efforts of establishing quantum networks [21,22].…”

“…Recently, faster single photon emission rates were measured by introducing ellipticity to bullseye structures, which broke the degeneracy of their polarization modes [7]. However, this broken degeneracy reduces the potential of elliptical gratings toward applications that require the coherent control of the quantum dot spin, which require the excitation of the spin circularly polarized light [14,18,19]. Furthermore, the impact of bullseye antennas on the optical properties of electrically charged dots at high magnetic fields, which offer such a spin qubit for quantum information processing [13][14][15][16][17][18][19], has yet to be explored.…”

“…In addition, the simulated far field emission pattern is polarization independent. This polarization independence positions bullseye antennas promising for the coherent control of the spin of electrically charged quantum dots coupled to the antenna, which typically requires pulses of circularly polarized light [14,18,19].…”

“…These differences in the intensity arise due to a small spectral splitting of polarization modes of this particular antenna due to fabrication imperfections (see supplementary material). Despite such quantitative differences, the ability to access quantum dots with light beams orthogonal to each other is crucial for the realization of pulse sequences for coherently controlling the quantum dots spin for quantum information processing, which typically require circularly polarized light [14,18,19].…”