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:1609.03474 · Nature Communications

Hong-Ou-Mandel experiment for temporal investigation of single-electron fractionalization

Vincent Freulon, Arthur Marguerite, Jean‐Marc Berroir, Bernard Plaçais, A. Cavanna, Yong Jin, Gwendal Fève

Published Apr 21, 2015• 135 citations
arXivHTMLPDF

Abstract

Coulomb interaction has a striking effect on electronic propagation in one-dimensional conductors. The interaction of an elementary excitation with neighbouring conductors favours the emergence of collective modes, which eventually leads to the destruction of the Landau quasiparticle. In this process, an injected electron tends to fractionalize into separated pulses carrying a fraction of the electron charge. Here we use two-particle interferences in the electronic analogue of the Hong-Ou-Mandel experiment in a quantum Hall conductor at filling factor 2 to probe the fate of a single electron emitted in the outer edge channel and interacting with the inner one. By studying both channels, we analyse the propagation of the single electron and the generation of interaction-induced collective excitations in the inner channel. These complementary pieces of information reveal the fractionalization process in the time domain and establish its relevance for the destruction of the quasiparticle, which degrades into the collective modes.

DOI
10.1038/ncomms7854

Related papers

Exchange-phase erasure in anyonic Hong-Ou-Mandel interferometry

Sushanth Varada, Christian Spånslätt, Matteo Acciai

Two-particle interferometry is an important tool for extracting the exchange statistics of quantum particles. We theoretically investigate the prospects of such interferometry to probe the statistics of pointlike anyonic excitations injected in a Hong-Ou-Mandel (HOM) setup based on a quantum point contact device in the fractional quantum Hall regime. We compute the standard HOM ratio, i.e., the ratio of tunneling noises for two- and one-particle injections, and find that for pointlike anyons it only depends on the temperature and the anyon scaling dimension. Importantly, the latter is not necessarily related to the exchange phase. In fact, we establish that the HOM ratio does not reveal the exchange phase of the injected anyons: For injection-time delays that are small compared to the thermal timescale, we find that the exchange phase accumulated due to time-domain braiding between injected and thermally activated anyons is erased due to two mutually canceling subprocesses. In contrast, for time delays large compared to the thermal time, only a single subprocess contributes to the braiding, but the accumulated phase is canceled in the HOM ratio. These findings suggest caution when interpreting HOM interferometry experiments with anyons, and approaches beyond the standard HOM ratio are thus necessary to extract anyonic statistics with two-particle interferometry experiments.

arXiv:2503.01678•Physical review. B./Physical review. B•May 28, 2025•3 citations

Charge and energy fractionalization mechanism in one-dimensional channels

Matteo Acciai, Alessio Calzona, Giacomo Dolcetto +2 more

We study the problem of injecting single electrons into interacting one-dimensional quantum systems, a fundamental building block for electron quantum optics. It is well known that such injection leads to charge and energy fractionalization. We elucidate this concept by calculating the nonequilibrium electron distribution function in the momentum and energy domains after the injection of an energy-resolved electron. Our results shed light on how fractionalization occurs via the creation of particle-hole pairs by the injected electron. In particular, we focus on systems with a pair of counterpropagating channels, and we fully analyze the properties of each chiral fractional excitation which is created by the injection. We suggest possible routes to access their energy and momentum distribution functions in topological quantum Hall or quantum spin-Hall edge states.

arXiv:1705.01055•Physical review. B./Physical review. B•Aug 22, 2017•19 citations

Decoherence of single electron wavepackets in the edge channels of the integer quantum Hall effect

Vincent Freulon

Cette thèse est consacrée à l'étude de la décohérence de paquets d'onde mono-électroniques injectés dans un conducteur quantique balistique. Les paquets d'onde sont générés à l'aide d'une capacité mésoscopique, utilisée comme source d'électrons uniques, qui sont émis à la demande dans le canal de bord externe de l'effet Hall quantique entier. Deux telles sources indépendantes et synchronisées sont positionnées sur les bras d'entrée d'une lame séparatrice électronique. La mesure des fluctuations (bruit) du courant dans les bras de sortie permet de caractériser les interférences à deux électrons se produisant sur la lame séparatrice. De cette manière, on réalise l'analogue électronique de l'interféromètre de Hong-Ou-Mandel (HOM). Il apparaît que le contraste de la figure d'interférence dépend de la forme des paquets d'onde injectés. Cette perte de cohérence est imputée au couplage capacitif, dû à l'interaction coulombienne, entre le canal de bord externe et les autres canaux de bord co-propageants, qui constituent un environnement contrôlé pour le canal externe. Afin de valider cette hypothèse, une seconde expérience est réalisée. La capacité mésoscopique y est utilisée dans un autre régime de fonctionnement, dans lequel elle permet de générer une excitation collective de la densité de charge du canal externe, appelée magnéto-plasmon de bord. En caractérisant la propagation du magneto-plasmon de bord en fonction de la fréquence d'excitation, on peut sonder l'interaction Coulombienne entre deux canaux de bord. Ces mesures montrent que cette interaction est responsable de l'apparition de deux modes propres de la propagation : un mode "chargé" rapide et un mode "neutre" lent. Elles permettent de caractériser quantitativement la vitesse de propagation du mode neutre. Les résultats de cette seconde expérience sont ensuite utilisés pour établir que la perte de contraste, observée dans l'expérience HOM, est essentiellement due à l'interaction entre canaux de bord. Ce couplage est responsable de la destruction des quasi-particules injectées par la source, un électron se séparant (ou fonctionnalisant) en deux pulses de charge e/2 au fil de sa propagation. Durant le processus de fractionnalisation, l'état généré dans le canal de bord externe s'intrique avec son environnement (canaux de bord co-propageants) entraînant la réduction du contraste dans l'expérience HOM. Ces observations ouvrent la voie à de nouvelles expériences plus complexes telles que la tomographie de l'état du paquet d'onde sur la lame séparatrice (pour valider complètement le scénario de destruction des quasi-particules) ou la protection de la cohérence de l'état dans le canal de bord externe.

•Oct 24, 2014•0 citations

Taming electronic decoherence in one-dimensional chiral ballistic quantum conductors

Clément Cabart, Benjamin Roussel, Gwendal Fève +1 more

Although interesting per se, decoherence and relaxation of single-electron excitations induced by strong effective screened Coulomb interactions in Quantum Hall edge channels are an important challenge for the applications of electron quantum optics in quantum information and quantum sensing. In this paper, we study intrinsic single-electron decoherence within an ideal single-electron channel with long-range effective Coulomb interactions to determine the influence of the material and sample properties. We find that weak-coupling materials characterized by a high velocity of hot-electron excitations may offer interesting perspectives for limiting intrinsic decoherence due to electron/electron interactions. We discuss quantitively how extrinsic decoherence due to the coupling with the channel's electromagnetic environment can be efficiently inhibited in specifically designed samples at $\ensuremath{\nu}=2$ with one closed edge channel and we propose a realistic geometry for testing decoherence control in a Hong-Ou-Mandel experiment.

arXiv:1804.04054•Physical review. B./Physical review. B•Oct 5, 2018•36 citations

Fractional Charge Determination via Quantum Shot Noise Measurements

Moty Heiblum

Charge excitations in a two dimensional electron gas, under a quantizing magnetic field and in the fractional quantum Hall effect regime, flow in one dimensional-like strips along the edges of the sample. These excitations (quasiparticles) may be independent or condense into an interacting chiral Luttinger liquid. Adding a backscattering potential, which reflects a forward propagating quasiparticle to a backward propagating one, partitions the stream of quasiparticles and induces quantum shot noise. The noise is proportional to quasiparticles charge and may be affected by their mutual interactions. The dependence of the determined charge on the temperature, excitation energy, and partitioning will be describes for a few fractional states, revealing in some cases a universal behavior.

arXiv:0912.4868•WORLD SCIENTIFIC eBooks•Aug 1, 2010•5 citations

Transient Features in Charge Fractionalization, Local Equilibration and Non-equilibrium Bosonization

Alexander Schneider, Mirco Milletari, Bernd Rosenow

In quantum Hall edge states and in other one-dimensional interacting systems, charge fractionalization can occur due to the fact that an injected charge pulse decomposes into eigenmodes propagating at different velocities. If the original charge pulse has some spatial width due to injection with a given source-drain voltage, a finite time is needed until the separation between the fractionalized pulses is larger than their width. In the formalism of non-equilibrium bosonization, the above physics is reflected in the separation of initially overlapping square pulses in the effective scattering phase. When expressing the single particle Green's function as a functional determinant of counting operators containing the scattering phase, the time evolution of charge fractionalization is mathematically described by functional determinants with overlapping pulses. We develop a framework for the evaluation of such determinants, describe the system's equilibration dynamics, and compare our theoretical results with recent experimental findings.

arXiv:1610.02036•SciPost Physics•Feb 25, 2017•5 citations
Coulomb interaction has a striking effect on electronic propagation in one-dimensional conductors. The interaction of an elementary excitation with neighbouring conductors favours the emergence of collective modes, which eventually leads to the destruction of the Landau quasiparticle. In this process, an injected electron tends to fractionalize into separated pulses carrying a fraction of the electron charge. Here we use two-particle interferences in the electronic analogue of the Hong-Ou-Mandel experiment in a quantum Hall conductor at filling factor 2 to probe the fate of a single electron emitted in the outer edge channel and interacting with the inner one. By studying both channels, we analyse the propagation of the single electron and the generation of interaction-induced collective excitations in the inner channel. These complementary pieces of information reveal the fractionalization process in the time domain and establish its relevance for the destruction of the quasiparticle, which degrades into the collective modes.
Two-particle interferometry is an important tool for extracting the exchange statistics of quantum particles. We theoretically investigate the prospects of such interferometry to probe the statistics of pointlike anyonic excitations injected in a Hong-Ou-Mandel (HOM) setup based on a quantum point contact device in the fractional quantum Hall regime. We compute the standard HOM ratio, i.e., the ratio of tunneling noises for two- and one-particle injections, and find that for pointlike anyons it only depends on the temperature and the anyon scaling dimension. Importantly, the latter is not necessarily related to the exchange phase. In fact, we establish that the HOM ratio does not reveal the exchange phase of the injected anyons: For injection-time delays that are small compared to the thermal timescale, we find that the exchange phase accumulated due to time-domain braiding between injected and thermally activated anyons is erased due to two mutually canceling subprocesses. In contrast, for time delays large compared to the thermal time, only a single subprocess contributes to the braiding, but the accumulated phase is canceled in the HOM ratio. These findings suggest caution when interpreting HOM interferometry experiments with anyons, and approaches beyond the standard HOM ratio are thus necessary to extract anyonic statistics with two-particle interferometry experiments.
We study the problem of injecting single electrons into interacting one-dimensional quantum systems, a fundamental building block for electron quantum optics. It is well known that such injection leads to charge and energy fractionalization. We elucidate this concept by calculating the nonequilibrium electron distribution function in the momentum and energy domains after the injection of an energy-resolved electron. Our results shed light on how fractionalization occurs via the creation of particle-hole pairs by the injected electron. In particular, we focus on systems with a pair of counterpropagating channels, and we fully analyze the properties of each chiral fractional excitation which is created by the injection. We suggest possible routes to access their energy and momentum distribution functions in topological quantum Hall or quantum spin-Hall edge states.
Cette thèse est consacrée à l'étude de la décohérence de paquets d'onde mono-électroniques injectés dans un conducteur quantique balistique. Les paquets d'onde sont générés à l'aide d'une capacité mésoscopique, utilisée comme source d'électrons uniques, qui sont émis à la demande dans le canal de bord externe de l'effet Hall quantique entier. Deux telles sources indépendantes et synchronisées sont positionnées sur les bras d'entrée d'une lame séparatrice électronique. La mesure des fluctuations (bruit) du courant dans les bras de sortie permet de caractériser les interférences à deux électrons se produisant sur la lame séparatrice. De cette manière, on réalise l'analogue électronique de l'interféromètre de Hong-Ou-Mandel (HOM). Il apparaît que le contraste de la figure d'interférence dépend de la forme des paquets d'onde injectés. Cette perte de cohérence est imputée au couplage capacitif, dû à l'interaction coulombienne, entre le canal de bord externe et les autres canaux de bord co-propageants, qui constituent un environnement contrôlé pour le canal externe. Afin de valider cette hypothèse, une seconde expérience est réalisée. La capacité mésoscopique y est utilisée dans un autre régime de fonctionnement, dans lequel elle permet de générer une excitation collective de la densité de charge du canal externe, appelée magnéto-plasmon de bord. En caractérisant la propagation du magneto-plasmon de bord en fonction de la fréquence d'excitation, on peut sonder l'interaction Coulombienne entre deux canaux de bord. Ces mesures montrent que cette interaction est responsable de l'apparition de deux modes propres de la propagation : un mode "chargé" rapide et un mode "neutre" lent. Elles permettent de caractériser quantitativement la vitesse de propagation du mode neutre. Les résultats de cette seconde expérience sont ensuite utilisés pour établir que la perte de contraste, observée dans l'expérience HOM, est essentiellement due à l'interaction entre canaux de bord. Ce couplage est responsable de la destruction des quasi-particules injectées par la source, un électron se séparant (ou fonctionnalisant) en deux pulses de charge e/2 au fil de sa propagation. Durant le processus de fractionnalisation, l'état généré dans le canal de bord externe s'intrique avec son environnement (canaux de bord co-propageants) entraînant la réduction du contraste dans l'expérience HOM. Ces observations ouvrent la voie à de nouvelles expériences plus complexes telles que la tomographie de l'état du paquet d'onde sur la lame séparatrice (pour valider complètement le scénario de destruction des quasi-particules) ou la protection de la cohérence de l'état dans le canal de bord externe.
Although interesting per se, decoherence and relaxation of single-electron excitations induced by strong effective screened Coulomb interactions in Quantum Hall edge channels are an important challenge for the applications of electron quantum optics in quantum information and quantum sensing. In this paper, we study intrinsic single-electron decoherence within an ideal single-electron channel with long-range effective Coulomb interactions to determine the influence of the material and sample properties. We find that weak-coupling materials characterized by a high velocity of hot-electron excitations may offer interesting perspectives for limiting intrinsic decoherence due to electron/electron interactions. We discuss quantitively how extrinsic decoherence due to the coupling with the channel's electromagnetic environment can be efficiently inhibited in specifically designed samples at $\ensuremath{\nu}=2$ with one closed edge channel and we propose a realistic geometry for testing decoherence control in a Hong-Ou-Mandel experiment.
Charge excitations in a two dimensional electron gas, under a quantizing magnetic field and in the fractional quantum Hall effect regime, flow in one dimensional-like strips along the edges of the sample. These excitations (quasiparticles) may be independent or condense into an interacting chiral Luttinger liquid. Adding a backscattering potential, which reflects a forward propagating quasiparticle to a backward propagating one, partitions the stream of quasiparticles and induces quantum shot noise. The noise is proportional to quasiparticles charge and may be affected by their mutual interactions. The dependence of the determined charge on the temperature, excitation energy, and partitioning will be describes for a few fractional states, revealing in some cases a universal behavior.
In quantum Hall edge states and in other one-dimensional interacting systems, charge fractionalization can occur due to the fact that an injected charge pulse decomposes into eigenmodes propagating at different velocities. If the original charge pulse has some spatial width due to injection with a given source-drain voltage, a finite time is needed until the separation between the fractionalized pulses is larger than their width. In the formalism of non-equilibrium bosonization, the above physics is reflected in the separation of initially overlapping square pulses in the effective scattering phase. When expressing the single particle Green's function as a functional determinant of counting operators containing the scattering phase, the time evolution of charge fractionalization is mathematically described by functional determinants with overlapping pulses. We develop a framework for the evaluation of such determinants, describe the system's equilibration dynamics, and compare our theoretical results with recent experimental findings.