Dephasing in a Mach-Zehnder Interferometer by an Ohmic Contact

Photonic polymeric structures and electrodynamics simulation method based on a coupled oscillator finite-difference time-domain (O-FDTD) approach

We use femtosecond laser-based two-photon polymerization (TPP) to fabricate a 2.5D micropillar array. Using an angular detection setup, we characterize the structure's scattering properties and compare the results against simulation results obtained from a novel electrodynamics simulation method. The algorithm employs a modified formulation of the Lorentz Oscillator Model and a leapfrog time differentiation to define a 2D coupled Oscillator Finite-Difference Time-Domain (O-FDTD). We validate the model by presenting several simulation examples that cover a wide range of photonic components, such as multi-mode interference splitters, photonic crystals, ring resonators, and Mach-Zehnder interferometers.

Phase-Coherent Dynamics of Quantum Devices with Local Interactions

This review illustrates how Local Fermi Liquid (LFL) theories describe the strongly correlated and coherent low-energy dynamics of quantum dot devices. This approach consists in an effective elastic scattering theory, accounting exactly for strong correlations. Here, we focus on the mesoscopic capacitor and recent experiments achieving a Coulomb-induced quantum state transfer. Extending to out-of-equilibrium regimes, aimed at triggered single electron emission, we illustrate how inelastic effects become crucial, requiring approaches beyond LFLs, shedding new light on past experimental data by showing clear interaction effects in the dynamics of mesoscopic capacitors.

Electronic heat flow and thermal shot noise in quantum circuits

When assembling individual quantum components into a mesoscopic circuit, the interplay between Coulomb interaction and charge granularity breaks down the classical laws of electrical impedance composition. Here we explore experimentally the thermal consequences, and observe an additional quantum mechanism of electronic heat transport. The investigated, broadly tunable test-bed circuit is composed of a micron-scale metallic node connected to one electronic channel and a resistance. Heating up the node with Joule dissipation, we separately determine, from complementary noise measurements, both its temperature and the thermal shot noise induced by the temperature difference across the channel. The thermal shot noise predictions are thereby directly validated, and the electronic heat flow is revealed. The latter exhibits a contribution from the channel involving the electrons' partitioning together with the Coulomb interaction. Expanding heat current predictions to include the thermal shot noise, we find a quantitative agreement with experiments.

Transmitting the quantum state of electrons across a metallic island with Coulomb interaction

The Coulomb interaction generally limits the quantum propagation of electrons. However, it can also provide a mechanism to transfer their quantum state over larger distances. Here, we demonstrate such a form of electron teleportation across a metallic island. This effect originates from the low-temperature freezing of the island's charge Q which, in the presence of a single connected electronic channel, enforces a one-to-one correspondence between incoming and outgoing electrons. Such faithful quantum state imprinting is established between well-separated injection and emission locations and evidenced through two-path interferences in the integer quantum Hall regime. The additional quantum phase of 2πQ/e, where e is the electron charge, may allow for decoherence-free entanglement of propagating electrons, and notably of flying qubits.