| 报告题目 | Dopant atoms and molecules in a semiconductor vacuum |
| 报告人 | Prof. Sven Rogge |
| 报告人单位 | University of New South Wales |
| 报告时间 | 2014-11-24 |
| 报告地点 | 合肥微尺度物质科学国家实验室九楼会议室（9004室） |
| 主办单位 | 合肥微尺度物质科学国家实验室 |
| 报告介绍 | 报告摘要： Semiconductor nano devices whose operation derives from the bound states of individual dopants have received considerable attention because of the promise for new functionalities in quantum electronics. Silicon offers a particularly interesting platform for single dopants because when isotopically purified, silicon acts as a “semiconductor vacuum” for spin, giving it extraordinary coherence. Although more difficult in silicon, optical control of single qubits is very attractive since it allows for precision quantum control with ultrahigh spectral resolution, and could enable long distance communication. This talk will discuss optical addressing and electrical detection of individual erbium dopants with exceptionally narrow line width. The hyperfine coupling to the Er nucleus is clearly resolved, which paves the way to single shot readout of the nuclear spin, and is the first step towards an optical interface to dopants in silicon. Furthermore, spatially resolved tunneling experiments performed by cryogenic scanning tunneling spectroscopy will also be discussed. They reveal the spectrum and wavefunction of both single dopants and exchange-coupled dopant molecules. Donors up to 5 nm below a silicon surface are measured, and exhibited quantum interference processes reflecting the valley degrees of freedom inherited from the silicon “semiconductor vacuum”. Finally, exchange-coupled solid-state molecules were studied. The signature of quantum correlations and entanglement were detected by spatially resolved local tunneling spectroscopy experiments in the single-hole tunneling regime. With increasing bond distance, evidence was found for a crossover from an uncorrelated state, to a correlated state. |
