Meng Khoon Tey

Abstract Topological phases have been widely studied in quantum pure states, where exact symmetries protect them. Such symmetry-protected topological phases have been observed in a range of systems, from solid-state materials to synthetic quantum platforms. Recent theory predicts that average symmetry-protected topological phases can also emerge in mixed quantum states that arise in realistic settings with decoherence or disorder, but experiments have not yet established them.

Suppressing high-frequency laser phase noise, particularly at frequencies near and beyond typical feedback bandwidths of a few megahertz, is a critical yet challenging task in many advanced applications. Feedforward-based methods generally outperform feedback in the high-frequency range, but their performances are more susceptible to perturbations. In this work, we focus on the Pound-Drever-Hall (PDH)-feedforward method that we demonstrated recently [Y.-X.

Abstract The notion of spontaneous symmetry breaking has been well established to characterize classical and quantum phase transitions of matter, such as condensation, crystallization or quantum magnetism. Generalizations of this paradigm to the time dimension can lead to a time crystal phase, which spontaneously breaks the time-translation symmetry of the system.