Figure 1

Hanbury Brown–Twiss experiment, sketch (inset) and sample. Schematic illustration based on the SEM picture of the sample. A perpendicular magnetic field $B=3.2\mathrm{T}$ is applied in order to work at filling factor $\nu =2$. The two edge channels are represented by blue lines. The emitter is placed on input 1, 2.5 microns before the electronic splitter whose gate voltage $V_{\mathrm{qpc}}$ is set to fully reflect the inner edge while the outer edge can be partially transmitted with tunable transmission $T$. The emitter is tunnel coupled to the outer edge channel with a transmission $D$ tuned by the gate voltage $V_g$. Electron emission is triggered by the excitation drive $V_{\mathrm{exc}}(t)$. Average measurements of the AC current generated by the source are performed on output 3, whereas output 4 is dedicated to the low frequency noise measurements $\delta S_{4,4}$. Inset: sketch of the Hanbury Brown–Twiss experiment. The average number of electrons (filled red dots) and holes (empty red dots) emitted on input 1 can be extracted from the current correlations between outputs 3 and 4.Reuse & Permissions

Figure 2

Low frequency correlations $\delta S_{4,4}=-S_{3,4}$ in units of $e^2{f}_d$ (left axis) and $A^2·{\mathrm{Hz}}^{-1}$ (right axis) as a function of the beam-splitter transmission $T$. Three types of rf drives are plotted, a sine wave at $D=1$ (black triangles), a sine wave at $D=0.3$ (red circles) and a square wave at $D=0.4$ (green squares). The solid lines represent adjustments with the expected $T(1-T)$ dependence.Reuse & Permissions

Figure 3

Calculations of $\delta n_e(ϵ)$ (right side) and $\delta n_h(ϵ)$ (left side) at $T_{\mathrm{el},1}=0$ using Floquet scattering theory. The energies are normalized by the dot level spacing $\Delta$. The black line is obtained with a sine drive at $D=1$, the red dashed one with a sine drive at $D=0.3$ and the green dashed one with a square drive at $D=0.4$. Note that in the case of a sine drive at $D=1$, electron-hole pairs generation by the absorption of $n$ photons of energy $h{f}_d$ is reflected by the steps of width $h{f}_d$ at energies $0$, $h{f}_d$, $2h{f}_d$, $3h{f}_d\dots$. At lower transmission $D=0.3$, the plateaus turn into peaks corresponding to the successive attempts of electrons/holes to leave the dot with an attempt frequency of $\Delta /h$. For a square drive, the spectral weight is centered around $\Delta /2$ with a width $\delta ϵ$ related to transmission $\delta ϵ\approx \frac{D\Delta }{2\pi }$. Note that $\delta n_e(ϵ)=\delta n_h(ϵ)$ (electron-hole symmetry) because the highest energy level of the dot is swept symmetrically around the Fermi energy. The grey dashed line represents $1-2f(ϵ)=\tanh \left(\frac{ϵ}{2k_B{T}_{\mathrm{el}}}\right)$, the fraction of excitations that are effectively counted in the HBT contribution $\delta N_{\mathrm{HBT}}$ at temperature $T_{\mathrm{el}}=150\mathrm{mK}$.Reuse & Permissions

Figure 4

(a) HBT contribution $\delta N_{\mathrm{HBT}}$ as a function of the dot transmission $D$ for a sine (left panel) and a square drive (right panel). The experimental points are represented by circles (sine drive) and squares (square drive). Dashed lines represent numerical evaluations of Eq. (6) using Floquet scattering theory at $T_{\mathrm{el},1}=T_{\mathrm{el},2}=0$ (red dashed line), $T_{\mathrm{el},2}=150\mathrm{mK}$, $T_{\mathrm{el},1}=0$ (blue line), $T_{\mathrm{el},1}=150\mathrm{mK}$, $T_{\mathrm{el},2}=0$ (blue dashed line), $T_{\mathrm{el},1}=150\mathrm{mK}$, $T_{\mathrm{el},2}=150\mathrm{mK}$ (black dashed line). (b) Schematic representation of particle emission. On these temporal traces, the filled (respectively empty) red symbols correspond to an occupied (respectively empty) level of the dot. An electron (respectively a hole) can be emitted every ${\tau }_0=h/\Delta$, time to perform one revolution inside the dot, when the occupied (respectively empty) level crosses the Fermi energy (${ϵ}_F=0$). Arrows represent a realization of particle emission. In the case of a sine drive (left-hand side), the energy rises slowly with time and particles can be emitted at low energy as compared to the square drive (right-hand side) for which the energy rises abruptly and particles are emitted at energy $\Delta /2$.Reuse & Permissions