43 research outputs found
Dynamic strain modulation of a nanowire quantum dot compatible with a thin-film lithium niobate photonic platform
The integration of on-demand single photon sources in photonic circuits is a
major prerequisite for on-chip quantum applications. Among the various
high-quality sources, nanowire quantum dots can be efficiently coupled to
optical waveguides because of their preferred emission direction along their
growth direction. However, local tuning of the emission properties remains
challenging. In this work, we transfer a nanowire quantum dot on a bulk lithium
niobate substrate and show that its emission can be dynamically tuned by
acousto-optical coupling with surface acoustic waves. The purity of the single
photon source is preserved during the strain modulation. We further demonstrate
that the transduction is maintained even with a SiO2 encapsulation layer
deposited on top of the nanowire acting as the cladding of a photonic circuit.
Based on these experimental findings and numerical simulations, we introduce a
device architecture consisting of a nanowire quantum dot efficiently coupled to
a thin film lithium niobate rib waveguide and strain-tunable by surface
acoustic waves
Observation of reentrant metal-insulator transition in a random-dimer disordered SSH lattice
The interrelationship between localization, quantum transport, and disorder
has remained a fascinating focus in scientific research. Traditionally, it has
been widely accepted in the physics community that in one-dimensional systems,
as disorder increases, localization intensifies, triggering a metal-insulator
transition. However, a recent theoretical investigation [Phys. Rev. Lett. 126,
106803] has revealed that the interplay between dimerization and disorder leads
to a reentrant localization transition, constituting a remarkable theoretical
advancement in the field. Here, we present the experimental observation of
reentrant localization using an experimentally friendly model, a photonic SSH
lattice with random-dimer disorder, achieved by incrementally adjusting
synthetic potentials. In the presence of correlated on-site potentials, certain
eigenstates exhibit extended behavior following the localization transition as
the disorder continues to increase. We directly probe the wave function in
disordered lattices by exciting specific lattice sites and recording the light
distribution. This reentrant phenomenon is further verified by observing an
anomalous peak in the normalized participation ratio. Our study enriches the
understanding of transport in disordered mediums and accentuates the
substantial potential of integrated photonics for the simulation of intricate
condensed matter physics phenomena
Fully quantum mechanical dynamic analysis of single-photon transport in a single-mode waveguide coupled to a traveling-wave resonator
We analyze the dynamics of single photon transport in a single-mode waveguide
coupled to a micro-optical resonator using a fully quantum mechanical model. We
examine the propagation of a single-photon Gaussian packet through the system
under various coupling conditions. We review the theory of single photon
transport phenomena as applied to the system and we develop a discussion on the
numerical technique we used to solve for dynamical behavior of the quantized
field. To demonstrate our method and to establish robust single photon results,
we study the process of adiabatically lowering or raising the energy of a
single photon trapped in an optical resonator under active tuning of the
resonator. We show that our fully quantum mechanical approach reproduces the
semi-classical result in the appropriate limit and that the adiabatic invariant
has the same form in each case. Finally, we explore the trapping of a single
photon in a system of dynamically tuned, coupled optical cavities.Comment: 24 pages, 10 figure
Reconfigurable frequency coding of triggered single photons in the telecom C--band
In this work, we demonstrate reconfigurable frequency manipulation of quantum
states of light in the telecom C-band. Triggered single photons are encoded in
a superposition state of three channels using sidebands up to 53 GHz created by
an off-the-shelf phase modulator. The single photons are emitted by an
InAs/GaAs quantum dot grown by metal-organic vapor-phase epitaxy within the
transparency window of the backbone fiber optical network. A cross-correlation
measurement of the sidebands demonstrates the preservation of the single photon
nature; an important prerequisite for future quantum technology applications
using the existing telecommunication fiber network.Comment: Samuel Gyger and Katharina D. Zeuner contributed equall
Resonance fluorescence from waveguide-coupled strain-localized two-dimensional quantum emitters
Efficient on-chip integration of single-photon emitters imposes a major
bottleneck for applications of photonic integrated circuits in quantum
technologies. Resonantly excited solid-state emitters are emerging as
near-optimal quantum light sources, if not for the lack of scalability of
current devices. Current integration approaches rely on cost-inefficient
individual emitter placement in photonic integrated circuits, rendering
applications impossible. A promising scalable platform is based on
two-dimensional (2D) semiconductors. However, resonant excitation and
single-photon emission of waveguide-coupled 2D emitters have proven to be
elusive. Here, we show a scalable approach using a silicon nitride photonic
waveguide to simultaneously strain-localize single-photon emitters from a
tungsten diselenide (WSe2) monolayer and to couple them into a waveguide mode.
We demonstrate the guiding of single photons in the photonic circuit by
measuring second-order autocorrelation of g and
perform on-chip resonant excitation yielding a g. Our
results are an important step to enable coherent control of quantum states and
multiplexing of high-quality single photons in a scalable photonic quantum
circuit