Matter waves (de Broglie waves) are the wave-like behaviour exhibited by material particles, such as electrons, with a wavelength determined by the particle's momentum. The faster and more massive the particle, the shorter its wavelength, so wave behaviour is significant only for very small particles. This idea extends wave–particle duality from light to matter and underlies quantum mechanics.

物质波(德布罗意波)是电子等实物粒子所表现的波动行为,其波长由粒子的动量决定。粒子越快、质量越大,波长越短,故波动行为只对极小的粒子才显著。这一思想把波粒二象性从光推广到物质,是量子力学的基础。