Quantum-elevated chiral discrimination for biomolecules

Chiral discrimination of enantiomeric biomolecules is vital in chemistry, biology, and medicine. Conventional methods, relying on circularly polarized light, face weak chiroptical signals and potential photodamage. Despite extensive efforts to improve sensitivity under low-photon exposure, classical chiral probes remain fundamentally bound by the shot noise limit due to quantum fluctuations. To beat these limitations, we demonstrate quantum-elevated chiral discrimination using continuous-variable polarization-entangled states as moderate-photon flux, high-sensitivity, quantum noise-squeezed chiral probes. We achieve a 5-decibel improvement beyond the shot noise limit in distinguishing l- and d-amino acids in liquid phase. This nondestructive, biocompatible protocol enables high-sensitivity chiral analysis, with broad implications for drug development, biochemical research, environmental monitoring, and asymmetric synthesis.