低温センター談話会(Dr. Christopher BAUERLE)
- 東京大学低温センター3階 セミナー室
- Dr. Christopher BAUERLE (Institut Neel - CNRS Grenoble, France)
- Manipulating single electrons on the fly using a sound wave
- Surface acoustic waves (SAW) provide a promising platform to realize quantum optics experiments with electrons at the single particle level. Pioneering single-shot experiments have shown SAW-assisted electron transport between spatially separated quantum dots over a distance of 4 μm with an efficiency of about 92% [1,2]. More recently we have also been able to transfer spin information , demonstrating the potential of this technique for coherent long distant transfer between two static qubits.
Here we go an important step further. We couple two quantum channels by a tunnel barrier along a region of 2 μm. At the end of each channel a quantum dot is placed serving as single-electron source and detector, respectively. We demonstrate single-electron transport over a distance of 22 μm with efficiencies above 99%. Changing the energy detuning in the coupling region we can partition the electron on-demand into two paths. By gradually changing the barrier height we additionally observe tunnel oscillations of the probability that the electron ends up at the upper or the lower detector quantum dot. This finding demonstrates coherent manipulation of the electron quantum state on the fly .
Our results pave the way for the implementation of a solid-state flying qubit having high relevance in fundamental research and quantum information technology.
 S. Hermelin et al., Nature 477, 435 (2011)
 R. P. G. McNeil et al., Nature 477, 439 (2011)
 B. Bertrand et al. Nature Nanotechnology 11, 672 (2016)
 S. Takada, H. Edlbauer et al, to be published