Anticorrelation for conductance fluctuations in chaotic quantum dots

We investigate the correlation functions of mesoscopic electronic transport in open chaotic quantum dots with finite tunnel barriers in the crossover between Wigner-Dyson ensembles. Using an analytical stub formalism, we show the emergence of a depletion and amplification of conductance fluctuations as a function of tunnel barriers for both parametric variations of electron energy and magnetoconductance fields. Furthermore, even for pure Dyson ensembles, correlation functions of conductance fluctuations in chaotic quantum dots can exhibit anticorrelation. Experimental support to our findings is pointed out.

Figure 1

Correlation function as a function of the parametric variation of energy. Transition from Lorentzian (dashed lines) to anticorrelation (solid line) as a function of symmetric $\Gamma$. The inset diagram $(\delta \varepsilon /\gamma )\times \Gamma$ show values of the correlation function in each color.

Figure 2

The leftmost diagram is a diffuson and the middle and right are cooperons.

Figure 3

Typical dimensionless conductance $g$ as a function of $\varepsilon /\gamma$. Solid lines show the numerical results for a single realization of $H$, the dots indicate the maxima of $g$, and the dashed line is the $\varepsilon$-independent conductance average.

Figure 4

The top (bottom) diagram shows the density of peaks $\langle {\rho }_{\varepsilon }\rangle$ ($\langle {\rho }_X\rangle$) for parametric variation of the electron energy (perpendicular magnetic field). The darker and lighter regions are explained in the strip on the right.