Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:1504.06223 · Physical Review B

Towards high-cooperativity strong coupling of a quantum dot in a tunable microcavity

Lukas Greuter, Sebastian Starosielec, Andreas V. Kuhlmann, Richard John Warburton

Published Jul 9, 2015• 32 citations
arXivHTMLPDF

Abstract

We investigate the strong-coupling regime of a self-assembled quantum dot in a tunable microcavity with dark-field laser spectroscopy. The high quality of the spectra allows the line shapes to be analyzed revealing subtle quantum interferences. Agreement with a model calculation is achieved only by including exciton dephasing which reduces the cooperativity from a bare value of 9.0 to the time-averaged value 5.5. In the pursuit of high cooperativity, besides a high Q and low mode-volume cavity, we demonstrate that equal efforts need to be taken towards lifetime-limited emitter linewidths.

DOI
10.1103/physrevb.92.045302

Related papers

Towards high-cooperativity strong coupling of a quantum-dot in a tunable microcavity: the role of emitter broadening

Sebastian Starosielec, Lukas Greuter, Andreas V. Kuhlmann +1 more

We study single InGaAs quantum-dots within a tunable microcavity and observe a large Rabi splitting and high cooperativity (5.5). The dynamics are limited by spectral wandering; we propose an improved design towards ultrahigh cooperativity.

Conference on Lasers and Electro-Optics•Jan 1, 2016•0 citations

Luminescence spectra of quantum dots in microcavities. III. Multiple quantum dots

Fabrice P. Laussy, Arne Laucht, Elena del Valle +2 more

We discuss the spectral line shapes of $N$ quantum dots in strong coupling with the single mode of a microcavity in the presence of a continuous, incoherent pumping. Nontrivial features in the response of the system are induced by detuning the emitters or probing the direct exciton emission spectrum. We describe dark states, quantum nonlinearities, emission dips, and interferences and show how these various effects may coexist, giving rise to highly peculiar line shapes.

arXiv:1102.3874•Physical Review B•Nov 9, 2011•37 citations

Self-assembled quantum dots in a fully tunable microcavity

Lukas Greuter

The interaction of light with matter is at the heart of quantum optics, which itself enables insight into the fundamental aspects of quantum mechanics. First experimental access to this research field has been realized by coupling atoms to light. Here, the transition between discrete energy states of the atom is associated with the absorption and emission of a photon, a single quantum of the electromagnetic field. As a central aspect of quantum optics, the light-emitter interaction can be significantly enhanced by placing the emitter in optical cavity that is on resonance with the emitter. In recent years, this has led to a rapidly evolving research field known as cavity quantum electrodynamics (CQED). In CQED two different regimes are distinguished: the strong and the weak coupling regimes. In the strong coupling regime, the emitted photon is reflected from the cavity mirrors and eventually reabsorbed by the emitter. In contrast, the weak coupling regime describes the irreversible emission, where the photon leaks out of the cavity before it can be reabsorbed. Both the weak and strong coupling regimes enabled fundamental experiments for a better understanding of quantum optical phenomena. \n \n \n \nCQED grants access to the quantum world and hence offers potentially revolutionizing applications, particularly in the field of quantum information processing. A central aspect for the successful implementation of quantum applications is the system's scalability. Unfortunately, placing atoms deterministically inside a cavity remains technologically elaborate and hence minimizes the prospect of scaling a atom-CQED system. \n \nA possibility to address this issue is to implement CQED in the solid state, where sophisticated fabrication strategies allow miniaturization and scalability of the system. Particularly the development of self-assembled quantum dots (QD) in semiconductors represent a promising route. QDs can be considered as artificial atoms that mimic the atomic two-level system. These structures interact strongly with light and therefore have the potential for replacing atoms in CQED. As a central advantage, QDs are naturally trapped, which greatly simplifies the deterministic incorporation into the cavity. \n \nIn recent years, many efforts have been made to couple self-assembled QDs to microcavities. Generally, the successful implementation of CQED requires a cavity with a high quality factor Q and a low mode volume. In a majority of the approaches, the high Q/small mode volume cavities were monolithically defined around the QD, embedding the QD at a fixed position inside the cavity. Both the weak and strong coupling regimes have been reached with these systems. However, for future applications they suffer from several disadvantages. The fixed position of the QD inside the cavity minimizes the prospects for spectral tunability and spatial positioning the QD inside the cavity. Furthermore, prospects for further increasing of the cavity Q-factor and minimization of the mode volume remain limited in these systems. \n \nIn this thesis the mentioned disadvantages are addressed by developing a fully tunable miniaturized Fabry-Pérot microcavity with low mode volume. The design enables both spatial positioning of the emitter inside the cavity and spectral tunability. Successful coupling of a single QD to the microcavity is demonstrated including the strong coupling regime. Further a new approach to decrease the cavity mode volume is presented, where we demonstrate weak coupling is achieved

•Jan 1, 2015•0 citations

A Charge-Tunable Quantum Dot Deep in The Strong Coupling Regime of Cavity QED

Daniel Najer, Immo Söllner, Matthias C. Löbl +9 more

We present high-cooperativity (C up to 140) strong coupling of a charge-tunable InAs quantum dot embedded in a tunable Fabry-Pérot microcavity (Q=500,000). Via second-order correlation measurements we show high single-photon purity in the photon-blockade regime and pronounced vacuum Rabi oscillations in the photon-induced tunneling regime.

IEEE/LEOS Summer Topical Meetings•Jul 1, 2018•4 citations

Spontaneous emission properties of a quantum dot in an ultrahigh- Q cavity: Crossover from weak- to strong-coupling states and robust quantum interference

Jun-ichi Inoue, Tetsuyuki Ochiai, Kazuaki Sakoda

We theoretically discuss spontaneous emission properties of a quantum dot embedded in an ultrahigh-$Q$ microcavity, where a detuning between an excitation in the quantum dot and the cavity mode is taken into account. Both weak- and strong-coupling states are obtained under the ultrahigh-$Q$ condition. In the high-$Q$ weak-coupling case, the spontaneous emission spectrum shows a sharp dip, whose origin is a quantum interference. In the strong-coupling case, there is a region where both the Rabi splitting and the quantum interference contribute on an equal footing, referred to as a crossover region, where the spontaneous emission spectral shape is quite similar to that of the high-$Q$ weak-coupling state. The quantum interference is robust against the detuning.

Physical Review A•Jan 10, 2008•8 citations

Toward quantum entanglement in a quantum-dot nanocavity

H. M. Gibbs, G. Khitrova, E. S. Lee +4 more

Our semiconductor normal-mode-coupling microcavities, each containing a single narrow-linewidth quantum well (QW), exhibit record many-oscillator vacuum-field Rabi splitting (VRS). The question addressed here is: can the vacuum field be increased sufficiently by reducing the cavity-mode volume, so that a single quantum dot can exhibit VRS similar to an atom in a high-finesse cavity? The quantum-dot nanocavity has two advantages: a length close to the theoretical minimum and a much larger dipole moment; these permit strong coupling without an ultra high-Q cavity even for such a short length.

IEEE/LEOS Summer Topical Meetings•Jan 1, 1999•1 citation
We investigate the strong-coupling regime of a self-assembled quantum dot in a tunable microcavity with dark-field laser spectroscopy. The high quality of the spectra allows the line shapes to be analyzed revealing subtle quantum interferences. Agreement with a model calculation is achieved only by including exciton dephasing which reduces the cooperativity from a bare value of 9.0 to the time-averaged value 5.5. In the pursuit of high cooperativity, besides a high Q and low mode-volume cavity, we demonstrate that equal efforts need to be taken towards lifetime-limited emitter linewidths.
We discuss the spectral line shapes of NNN quantum dots in strong coupling with the single mode of a microcavity in the presence of a continuous, incoherent pumping. Nontrivial features in the response of the system are induced by detuning the emitters or probing the direct exciton emission spectrum. We describe dark states, quantum nonlinearities, emission dips, and interferences and show how these various effects may coexist, giving rise to highly peculiar line shapes.
The interaction of light with matter is at the heart of quantum optics, which itself enables insight into the fundamental aspects of quantum mechanics. First experimental access to this research field has been realized by coupling atoms to light. Here, the transition between discrete energy states of the atom is associated with the absorption and emission of a photon, a single quantum of the electromagnetic field. As a central aspect of quantum optics, the light-emitter interaction can be significantly enhanced by placing the emitter in optical cavity that is on resonance with the emitter. In recent years, this has led to a rapidly evolving research field known as cavity quantum electrodynamics (CQED). In CQED two different regimes are distinguished: the strong and the weak coupling regimes. In the strong coupling regime, the emitted photon is reflected from the cavity mirrors and eventually reabsorbed by the emitter. In contrast, the weak coupling regime describes the irreversible emission, where the photon leaks out of the cavity before it can be reabsorbed. Both the weak and strong coupling regimes enabled fundamental experiments for a better understanding of quantum optical phenomena. \n \n \n \nCQED grants access to the quantum world and hence offers potentially revolutionizing applications, particularly in the field of quantum information processing. A central aspect for the successful implementation of quantum applications is the system's scalability. Unfortunately, placing atoms deterministically inside a cavity remains technologically elaborate and hence minimizes the prospect of scaling a atom-CQED system. \n \nA possibility to address this issue is to implement CQED in the solid state, where sophisticated fabrication strategies allow miniaturization and scalability of the system. Particularly the development of self-assembled quantum dots (QD) in semiconductors represent a promising route. QDs can be considered as artificial atoms that mimic the atomic two-level system. These structures interact strongly with light and therefore have the potential for replacing atoms in CQED. As a central advantage, QDs are naturally trapped, which greatly simplifies the deterministic incorporation into the cavity. \n \nIn recent years, many efforts have been made to couple self-assembled QDs to microcavities. Generally, the successful implementation of CQED requires a cavity with a high quality factor Q and a low mode volume. In a majority of the approaches, the high Q/small mode volume cavities were monolithically defined around the QD, embedding the QD at a fixed position inside the cavity. Both the weak and strong coupling regimes have been reached with these systems. However, for future applications they suffer from several disadvantages. The fixed position of the QD inside the cavity minimizes the prospects for spectral tunability and spatial positioning the QD inside the cavity. Furthermore, prospects for further increasing of the cavity Q-factor and minimization of the mode volume remain limited in these systems. \n \nIn this thesis the mentioned disadvantages are addressed by developing a fully tunable miniaturized Fabry-Pérot microcavity with low mode volume. The design enables both spatial positioning of the emitter inside the cavity and spectral tunability. Successful coupling of a single QD to the microcavity is demonstrated including the strong coupling regime. Further a new approach to decrease the cavity mode volume is presented, where we demonstrate weak coupling is achieved
We theoretically discuss spontaneous emission properties of a quantum dot embedded in an ultrahigh-QQQ microcavity, where a detuning between an excitation in the quantum dot and the cavity mode is taken into account. Both weak- and strong-coupling states are obtained under the ultrahigh-QQQ condition. In the high-QQQ weak-coupling case, the spontaneous emission spectrum shows a sharp dip, whose origin is a quantum interference. In the strong-coupling case, there is a region where both the Rabi splitting and the quantum interference contribute on an equal footing, referred to as a crossover region, where the spontaneous emission spectral shape is quite similar to that of the high-QQQ weak-coupling state. The quantum interference is robust against the detuning.
Our semiconductor normal-mode-coupling microcavities, each containing a single narrow-linewidth quantum well (QW), exhibit record many-oscillator vacuum-field Rabi splitting (VRS). The question addressed here is: can the vacuum field be increased sufficiently by reducing the cavity-mode volume, so that a single quantum dot can exhibit VRS similar to an atom in a high-finesse cavity? The quantum-dot nanocavity has two advantages: a length close to the theoretical minimum and a much larger dipole moment; these permit strong coupling without an ultra high-Q cavity even for such a short length.