Perovskites have generated huge interest in recent years because of their potential for solid-state lighting and displays, despite lagging behind other state-of-the-art technologies in efficiency and longevity. Now two independent teams have reported light-emitting diodes (LEDs) based on perovskites that have surpassed a milestone in efficiency [Cao et al., Nature …

Quantum cryptography is an emerging technology in which two parties may simultaneously generate shared, secret cryptographic key material using the transmission of quantum states of light. A unique aspect of quantum cryptography is that Heisenberg’s uncertainty principle ensures that if Eve attempts to intercept and measure Alice’s quantum transmissions, her …