Phase-Stable Interferometric Time-bin Entanglement (PSITE)

Quantum networking using quantum entanglement is a potentially revolutionary technology with both anticipated application, such as “blind” quantum computing and secure communications, as well as a host of yet-to-be-discovered uses. To discover these such “killer apps” and reveal the true potential of quantum entanglement, scientist and engineers need standardized and reliable hardware to transmit and receive entangled quantum states of light. While demonstrating standardized devices is of the upmost importance, new technology should improve upon existing demonstrations. One of the largest challenges revealed for single-photon-based networking is successfully transmitting large number of entangled states. For the case of binary qubits (e.g., polarization), the dimensionality of possible entangled states scales as 2^n, where n is the number of single photons. However, increasing the number of entangled photon pairs to achieve a larger number of entangled states poses a critical problem when losses are introduced, exponentially reducing the probability of successful simultaneous transmission of all the qubits. Therefore, identifying and realizing an alternative solution that is both more robust to losses and scalable to larger number of entangled states is of critical importance. To address this challenge, PSI will team with Prof. Paul Kwiat (University of Illinois, Urbana Champaign, UIUC) and utilize the foundry services of Hyperlight to develop an on-chip lithium-niobate-based time-bin entanglement transceiver. This program will combine three key innovations. First, we will use time-bin encoding to greatly increase the dimensionality of entangled states while simultaneously reducing the impact of losses. Second, we will leverage commercially available thin-film lithium-niobate as a novel platform for quantum information, having exceptionally low losses and readily-available high-speed modulators and a native second-order nonlinearity to enables on-chip spontaneous parametric down-conversion. Third, we will design our devices to be phase-stable using active feedback and scalable to greater number of entangled states. This approach will result in a Phase Stable Interferometric Time-bin Entangled (PSITE) transceiver that will become a standardized component to facilitate exploring quantum-entanglement applications.