Single-electron coherence: Finite temperature versus pure dephasing

Single electron sources enable electron quantum optics experiments where single electrons emitted in a ballistic electronic interferometer plays the role of a single photons emitted in an optical medium in Quantum Optics. A qualitative step has been made with the recent generation of single charge levitons obtained by applying Lorentzian voltage pulse on the contact of the quantum conductor. Simple to realize and operate, the source emits electrons in the form of striking minimal excitation states called levitons. We review the striking properties of levitons and their possible applications in quantum physics to electron interferometry and entanglement. Copyright line will be provided by the publisher 1 Single electron sources In this introduction, we will distinguish single charge sources from coherent single electrons sources. The former have been developed for quantum metrology where the goal is to transfer an integer charge at high frequency f through a conductor with good accuracy to realize a quantized current source whose current I = ef shows metrological accuracy. The latter, the coherent single electrons source, aims at emitting (injecting) a single electron whose wave-function is well defined and controlled to realize further single electron coherent manipulation via quantum gates. The gates are provided by electronic beam-splitters made with Quantum Point Contacts or provided by electronic Mach-Zehnder and FabryProt interferometers. Here it is important that the injected single electron is the only excitation created in the conductor. The frequency f of injection is not chosen to have a large current, as current accuracy is not the goal, but only to get sufficient statistics on the electron transfer events to extract physical information. single charge sources for current standardsThe first manipulation of single charges trace back to the early 90's where physicists took advantage of charge quantization of a submicronic metallic island nearly isolated from leads by tunnel barriers. The finite energy E C = e 2 /2C to charge the small capacitor C with a single charge being larger than temperature (typically one kelvin for

“…The robustness of the 100% HOM dip to temperature for any voltage pulse shape and of the HOM leviton noise curve versus

τ

τ

for the case of a leviton.…”

Section: Levitons: Time‐resolved Single Electron With Minimal Excitatmentioning

confidence: 90%

Levitons for electron quantum optics

Glattli

Roulleau

2016

“…We compare our formulas with the numerical results of a Floquet calculation properly modeling the emission process from a realistic periodic source . This emitter consists of the mesoscopic capacitor : a quantum dot with discrete levels connected through a QPC to the edge state that is driven by a gate applying a periodic square drive

V false(t false)

.…”

Section: Hong–ou–mandel Electron Collisions In the Integer Quantum Hamentioning

confidence: 99%

Electronic quantum optics beyond the integer quantum Hall effect

Ferraro

Jonckheere

Rech

et al. 2016

The analog of two seminal quantum optics experiments are considered in a condensed matter setting with single electron sources injecting electronic wave packets on edge states coupled through a quantum point contact. When only one electron is injected, the measurement of noise correlations at the output of the quantum point contact corresponds to the Hanbury-Brown and Twiss setup. When two electrons are injected on opposite edges, the equivalent of the Hong-Ou-Mandel collision is achieved, exhibiting a dip as in the coincidence measurements of quantum optics. The Landauer-Buttiker scattering theory is used to first review these phenomena in the integer quantum Hall effect, next, to focus on two more exotic systems: edge states of two dimensional topological insulators, where new physics emerges from time reversal symmetry and three electron collisions can be achieved; and edges states of a hybrid Hall/superconducting device, which allow to perform electron quantum optics experiments with Bogoliubov quasiparticles.Comment: 13 pages, 10 figures, invited contribution for a focus issue on "Single-electron control in solid-state devices

“…The state of injected electrons depends on the type of source and its working regime. Generally the state emitted at zero ambient temperature is pure and it can be characterized by a wave function (). For illustrative purposes, we present below three known analytical expression for a wave function of a single‐electron injected on the top of the Fermi sea in different regimes.…”

Section: Single‐electron Excitationsmentioning

confidence: 99%

Heat and charge transport measurements to access single‐electron quantum characteristics

Moskalets

Haack

2016

Self Cite

In the framework of the Floquet scattering‐matrix theory, we discuss how electrical and heat currents accessible in mesoscopics are related to the state of excitations injected by a single‐electron source into an electron waveguide. We put forward an interpretation of a single‐particle heat current, which differs essentially from that of an electrical current. We show that the knowledge of both a time‐dependent electrical current and a time‐dependent heat current allows the full reconstruction of a single‐electron wave function. In addition, we compare electrical and heat shot noise caused by splitting of a regular stream of single‐electron excitations. If only one stream impinges on a wave splitter, the heat shot noise is proportional to the well‐known expression of the charge shot noise, reflecting the partitioning of the incoming single particles. The situation differs when two electronic streams collide at the wave splitter. The shot noise suppression, due to the Pauli exclusion principle, is governed by different overlap integrals in the case of charge and of heat.