Quantum meta-device for ultrasensitive displacement metrology

A displacement measurement system, comprising:

• a) an entangled state light source generator adapted to emit a linearly-polarized photon pair;
• the linearly-polarized photon pair being an entangled photon pair;
• b) a meta-device element adapted to receive the linearly-polarized photon pair and converts the same to a circularly-polarized photon pair;
• c) a first polarization beam splitter adapted to split one or both ways of the circularly- polarized photon pair into a left-handed rotational photon and a right-handed rotational photon, and to output the left-handed rotational photon and the right- handed rotational photon via a first port and a second port of the first polarization beam splitter respectively;
• and
• d) a computing section adapted to compute a correlated count reading between the first and second ports of the first polarization beam splitter, and to determine a displacement of the meta-device element.