Perfect Chirality with Imperfect Polarization

Lang, Ben; McCutcheon, Dara P. S.; Harbord, Edmund; Young, Andrew; Oulton, Ruth

doi:10.1103/physrevlett.128.073602

Cited by 15 publications

(19 citation statements)

References 50 publications

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“…In this way we observe a non-chirally-coupled dot with an extremely large radiative decay rate of 172 ns 1 (606 ps lifetime), corresponding to a 202 fold Purcell enhancement. We also observe chiral routing of spin-carrying photons from a QD near a Cpoint with a 51 fold Purcell factor, substantially outperforming previous demonstrations with nanobeam 25 , nanofiber 29 , and PCWs 24,28,[30][31][32][33][34] . Together, these results constitute significant progress towards reaching the threshold for scalable chiral networks.…”

Section: Introductionmentioning

confidence: 54%

Observation of large spontaneous emission rate enhancement of quantum dots in a broken-symmetry slow-light waveguide

Siampour

O’Rourke

Brash

et al. 2022

Preprint

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Quantum states of light and matter can be manipulated on the nanoscale to provide a technological resource for aiding the implementation of scalable photonic quantum technologies [1-3]. Experimental progress relies on the quality and efficiency of the coupling between photons and internal states of quantum emitters [4-6]. Here we demonstrate a nanophotonic waveguide platform with embedded quantum dots (QDs) that enables both Purcell-enhanced emission and strong chiral coupling. The design uses slow-light effects in a glide-plane photonic crystal waveguide with QD tuning to match the emission frequency to the slow-light region. Simulations were used to map the chirality and Purcell enhancement depending on the position of a dipole emitter relative to the air holes. The highest Purcell factors and chirality occur in separate regions, but there is still a significant area where high values of both can be obtained. Based on this, we first demonstrate a record large radiative decay rate of 17 ns^-1 (60 ps lifetime) corresponding to a 20 fold Purcell enhancement. This was achieved by electric-field tuning of the QD to the slow-light region and quasi-resonant phonon-sideband excitation. We then demonstrate a 5 fold Purcell enhancement for a dot with high degree of chiral coupling to waveguide modes, substantially surpassing all previous measurements. Together these demonstrate the excellent prospects for using QDs in scalable implementations of on-chip spin-photonics relying on chiral quantum optics.

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Section: Introductionmentioning

confidence: 54%

Observation of large spontaneous emission rate enhancement of quantum dots in a broken-symmetry slow-light waveguide

Siampour

O’Rourke

Brash

et al. 2022

Preprint

View full text Add to dashboard Cite

show abstract

“…Similar to previous discussions, the interaction strengths with channel A and B [see Eqs. (14,15)] are written as…”

Section: Periodical Interference Behavior Modulated By Giant Emitter'...mentioning

confidence: 99%

“…As discussed in Refs. [11][12][13][14][15], chiral emission can be observed via the subwavelength confinement in nanophotonic systems, which opens the possibilities to realize cascaded quantum networks. Moreover, when considering an emitter coupling to the bandgaps of a bath [16][17][18][19][20][21][22], photonic bound states (in the form of an evanescent field) emerge [23].…”

Section: Introductionmentioning

confidence: 99%

Unconventional Quantum Electrodynamics with Hofstadter-Ladder Waveguide

Wang,

Gao,

et al. 2022

Preprint

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We propose a novel quantum electrodynamics (QED) platform where quantum emitters interact with a Hofstadter-ladder waveguide. We demonstrate several intriguing phenomena stemming from the exotic dispersion relation and vacuum mode properties led by the effective spin-orbit coupling, which have no analog in other QED setups. First, by assuming emitter's frequency to be resonant with the lower band, we find that the spontaneous emission is chiral with most photonic field decaying unidirectionally. Both numerical and analytical results indicate that the Hofstadter-ladder waveguide can be engineered as a well-performed chiral quantum bus. Second, the dynamics of emitters of giant atom form is explored by considering their frequencies below the lower band. Due to quantum interference, we find that both the emitter-waveguide interaction and the amplitudes of bound states are periodically modulated by giant emitter's size. The periodical length depends on the positions of energy minima points induced by the spin-orbit coupling. Last, we consider the interaction between two giant emitters mediated by bound states, and find that their dipole-dipole interaction vanishes (is enhanced) when maximum destructive (constructive) interference happens.

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“…This deforms the phase structures continuously, preserving the two singularities until they mutually annihilate on the equator for a linear polarisation. This highlights that for any polarisation there is a dipole that decouples from the forward mode and another the backward one (the singularities), with the two coinciding only for a linear polarisation [14].…”

mentioning

confidence: 97%

“…However one can construct the arbitrary complex dipole d = αd x + βd y . Our previous work [14], has highlighted that even when emitters are placed at an elliptical point, emission may be made unidirectional by matching the helicity and eccentricity of the ellipse and the dipole, but putting the long axes of the two ellipses orthogonal. This negates the backscattered component so that only forward scattering can occur.…”

mentioning

confidence: 99%

Reflection by two level system: phase singularities on the Poincaré hypersphere

Lang¹,

Harbord²,

Oulton³

2023

Preprint

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We consider the reflection of a photon by a two-level system in a quasi-one-dimensional waveguide. This is important in part because it forms the backdrop for more complicated proposals where many emitters are coupled to the waveguide: leading to super and subradiant coupling even when the emitters are distant. The incorporation of chiral effects, for example unidirectional emission of dipole emitters, has already led to rich physics such as dimer coupling. However, chirality is not the only effect of the dipole, as we explore from a phase singularity perspective. We demonstrate that control of the dipole allows a rich variety of control of the phase and amplitude of the scattered light in both directions. This expands the scope for the physics of 1D chains of emitters.

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Perfect Chirality with Imperfect Polarization

Cited by 15 publications

References 50 publications

Observation of large spontaneous emission rate enhancement of quantum dots in a broken-symmetry slow-light waveguide

Observation of large spontaneous emission rate enhancement of quantum dots in a broken-symmetry slow-light waveguide

Unconventional Quantum Electrodynamics with Hofstadter-Ladder Waveguide

Reflection by two level system: phase singularities on the Poincaré hypersphere

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