Quantum Dot technology is a very real thing in video. I haven't a clue what they would be used for on the audio side. Presumably just snake oil marketing buzz words...I can state with pride, however, that I never fell for the quantum dot thing (preens self).
https://en.wikipedia.org/wiki/Quantum_dot_display
https://www.cnet.com/tech/home-entertainment/samsung-qd-oled-tv-tech-explained-welcome-quantum-dot-era/