Researchers show how to certify entangled qubits without full device control

Researchers at the Indian Institute of Technology Hyderabad have developed a new protocol to certify entangled basis measurements using a semi-device-independent approach in a prepare-measure scenario. The work details a method for verifying entanglement without requiring full control over the quantum device, potentially easing the path toward practical verification of quantum systems. This protocol focuses on a tri-partite system where two senders can each transmit 2m inputs to a single receiver, and the researchers demonstrate that nonlinear witnesses within a classical causal model exceed classical bounds. The results show this approach can certify both the entangled basis measurement and the states prepared by the two senders. A new certification protocol allows verification of entangled basis measurements with relaxed requirements for quantum device control, a departure from traditional methods demanding complete control. This…