Phys.org November 21, 2022 In quantum communications with qubits, the superposition makes it so a quantum pulse cannot be copied. However, with only two levels of superposition, qubits have limited storage space and low tolerance for interference. An international team of researchers (USA – University of Pennsylvania, Duke University, City University of New York, Spain, Italy) has created a chip that outstrips the security and robustness of existing quantum communications hardware. The device’s four-level qudits enable significant advances in quantum cryptography, raising the maximum secrete key rate for information exchange from 1 bit per pulse to 2 bits per pulse. […]
Category Archives: Qudits
New measurements quantifying qudits provide glimpse of quantum future
Science Daily October 13, 2022 An international team of researchers (USA – Oak Ridge National Laboratory, Purdue University, industry, Switzerland) combined state-of-the-art frequency-bin production with state-of-the-art light sources to develop an effective technique to characterize high-dimensional qudit entanglement. They fully characterized an entangled pair of eight-level qudits, which formed a 64-dimensional quantum space — quadrupling the previous record for discrete frequency modes. The researchers began their experiments by shining a laser into a micro-ring resonator — a circular, on-chip device fabricated and designed to generate nonclassical light. This powerful photon source which took 1 square millimeter of space and allowed […]