Yu-Ao Chen

Abstract Reversing unknown quantum dynamics is vital for quantum control and learning, yet full unitary inversion requires a resource-intensive O(d2) queries. Because many applications only require the reversed evolution for a given observable, a critical gap remains in understanding the minimal resources for such targeted reversal. Here, we address this by introducing shadow unitary inversion.

Long baseline diffraction-limited optical aperture synthesis technology by interferometry plays an important role in scientific study and practical application. In contrast to amplitude (phase) interferometry, intensity interferometry—which exploits the second-order coherence of thermal light—is robust against atmospheric turbulence and optical defects.

July 29, 2024• Physics 17, 118 By reducing the effect of systematic errors, researchers have created an atomic clock that sets a new record for precision. × The advent of atomic clocks in the 1950s marked a paradigm shift in our ability to measure time with ultrahigh precision. Today’s most precise devices are so accurate that, if you had started one ticking at the big bang, it would by now be off by barely a second.