Because eavesdropping changes the physical nature of the information, users in a quantum exchange can easily detect eavesdroppers. 偷聽兌換信息的物質性質，用戶在一量內交換能容易發現偷聽的人。
Bright soliton pairs propagating in the birefringent fiber with the anomalous dispersion exchange the energy periodically by the couple between them. 在反常色散的雙折射光纖中傳輸的亮孤子對之間由於耦合周期性地交換能量，一個亮孤子可把能量完全傳給另一個亮孤子，因此雙折射光纖可作亮孤子開關。
This condition effectively relaxes the momentum conservation requirement governing electron-photon energy transfer, which boosts the rate of light emission by the semiconductor. 運用這種現象將可突破電子與光子交換能量時的動量守恆限制，大幅提高半導體的發光效率。
