A series of recent experiments have shown that collision of ballistic electrons in semiconductors can be used to probe the indistinguishability of single-electron wavepackets. Perhaps surprisingly, their Coulomb interaction has not been seen due to screening. Here we show Coulomb-dominated collision of high-energy single electrons in counter-propagating ballistic edge states, probed by measuring partition statistics while adjusting the collision timing. Although some experimental data suggest antibunching behaviour, we show that this is not due to quantum statistics but to strong repulsive Coulomb interactions. This prevents the wavepacket overlap needed for fermionic exchange statistics but suggests new ways to utilize Coulomb interactions: microscopically isolated and time-resolved interactions between ballistic electrons can enable the use of the Coulomb interaction for high-speed sensing or gate operations on flying electron qubits.

最近的一系列实验表明，半导体中弹道电子的碰撞可以用来探测单电子波包的不可区分性。也许令人惊讶的是，由于筛选而没有发现它们的库仑相互作用。在这里，我们展示了反向传播弹道边缘态中高能单电子的库仑主导碰撞，通过测量分区统计数据同时调整碰撞时间来进行探测。尽管一些实验数据表明反聚束行为，但我们表明这不是由于量子统计而是由于强排斥库仑相互作用。这可以防止费米子交换统计所需的波包重叠，但提出了利用库仑相互作用的新方法：弹道电子之间的微观隔离和时间分辨相互作用可以使用库仑相互作用进行飞行电子量子位的高速传感或门操作。