However, (further application/studies are in need of understanding of atom-surface interaction, size-limit, ultracold atom base 면 cluster study 불가능, )
 QR 은 atom-surface interaction 을 이해하는 좋은 툴이자 좋은 mirror 이다. 근데 이거가 ultracold 일수도 있고 ㅇ
 Recently - half plane을 받을지.... , a totally new mechanism of matter-wave reflection has been demonstrated by observing quantum refleciton of metastable neon atoms from the solid surface. Quantum reflection is