SearcharxivSearch

arXiv subjects

Matthew Jordan

Publications and source records attributed to Matthew Jordan.

4 recordsLinked to original sources

The origin and influence of non-cavity modes in a micropillar Bragg microcavity

Controlling the photonic environment of emitters is essential to the design of classical and quantum light sources. We study the case of a dipole-like emitter in a cylindrical pillar etched into a planar Bragg microcavity, which is a common design of quantum-dot single photon source. In addition to the well-known cavity modes created by the high-reflectivity of the Bragg mirrors at small in-plane wavevectors, we show the presence of broad spectral features that play a key role in controlling photon collection efficiency and Purcell enhancement. These non-cavity modes are insensitive to the periodic index modulation of the Bragg reflectors, but arise from the cylindrical pillar geometry, as we show by comparison with simulations of uniform pillars, which reproduce the non-cavity modes. This approach provides a tool for understanding and modelling these often-disregarded decay channels as a function of source height, cavity dimensions and surface layers.

physics.optics

Tunable multi-photon correlations from a coherently driven quantum dot

Mixing the fields generated by different light sources has emerged as a powerful approach for engineering non-Gaussian quantum states. Understanding and controlling the resulting photon statistics is useful for emerging quantum technologies that are underpinned by interference. In this work, we investigate intensity correlation functions arising from the interference of resonance fluorescence from a quantum emitter with a coherent laser field. We show that the observed bunching behavior results from a subtle interplay between quantum interference and the normalization of the correlation functions. We show that by adjusting the mixing ratio and phase one can achieve full tunability of the second-order correlation, ranging from anti-bunching to bunching. We further extend our analysis to third-order correlation functions, both experimentally and theoretically, to provide new insights into the interpretation of higher-order correlations and offer practical tools for shaping quantum optical fields.

quant-ph

Probing Purcell enhancement and photon collection efficiency of InAs quantum dots at nodes of the cavity electric field

The interaction of excitonic transitions with confined photonic modes enables tests of quantum physics and design of efficient optoelectronic devices. Here we study how key metrics such as Purcell factor, beta-factor and collection efficiency are determined by the non-cavity modes which exist in real devices, taking the well-studied micropillar cavity as an example. Samples with dots at different positions in the cavity field allow us to quantify the effect of the non-cavity modes and show that the zero-phonon line and the phonon-assisted emission into the cavity mode HE11 is suppressed by positioning dots at the field node.

cond-mat.mes-hall

Direct-write projection lithography of quantum dot micropillar single photon sources

We have developed a process to mass-produce quantum dot micropillar cavities using direct-write lithography. This technique allows us to achieve high volume patterning of high aspect ratio pillars with vertical, smooth sidewalls maintaining a high quality factor for diameters below 2.0 $\mu$m. Encapsulating the cavities in a thin layer of oxide (Ta$_2$O$_5$) prevents oxidation in the atmosphere, preserving the optical properties of the cavity over months of ambient exposure. We confirm that single dots in the cavities can be deterministically excited to create high purity indistinguishable single photons with interference visibility $(96.2\pm0.7)\%$.

physics.app-ph