Departamento de Química Física, UPV/EHU, Apdo. 644, 48080 Bilbao, Spain.
Phys Rev Lett. 2013 Nov 22;111(21):213001. doi: 10.1103/PhysRevLett.111.213001. Epub 2013 Nov 20.
Sending multiple messages on qubits encoded in different vibrational modes of cold atoms or ions along a transmission waveguide requires us to merge first and then separate the modes at input and output ends. Similarly, different qubits can be stored in the modes of a trap and be separated later. We design the fast splitting of a harmonic trap into an asymmetric double well so that the initial ground vibrational state becomes the ground state of one of two final wells, and the initial first excited state becomes the ground state of the other well. This might be done adiabatically by slowly deforming the trap. We speed up the process by inverse engineering a double-function trap using dynamical invariants. The separation (demultiplexing) followed by an inversion of the asymmetric bias and then by the reverse process (multiplexing) provides a population inversion protocol based solely on trap reshaping.
发送多个信息到冷原子或离子的不同振动模式的量子比特，需要我们在输入和输出端先合并再分离模式。类似地，不同的量子比特可以存储在阱的模式中，然后再分离。我们设计了将谐波阱快速分裂成非对称双阱，使得初始基频振动态成为两个最终阱之一的基态，初始第一激发态成为另一个阱的基态。这可以通过缓慢变形阱来实现。我们通过使用动力学不变量来对双功能阱进行逆向工程，从而加速了这个过程。非对称偏置的分离（解复用），然后反转偏置，然后再进行相反的过程（复用），提供了一种仅基于阱形状变化的粒子数反转协议。
