Prof. Lev Vaidman works on fundamental problems in the foundations of quantum mechanics, quantum information, and quantum optics. He develops interpretations of quantum theory, searches for novel quantum effects, takes part in quantum optics experiments demonstrating peculiar features of quantum mechanics, and designs quantum devices for practical applications.

Research achievements include: Solving the problem of introducing probability in the framework of the many-worlds interpretation and identifying constraints leading to the Born Rule. Introducing, analyzing, and developing counterfactual quantum communication protocols in which no particles are present in the transmission channel. Introducing, analyzing, and implementing in laboratories novel measurement schemes in quantum mechanics: measurements of nonlocal variables, interaction-free measurements, protective measurements, and weak measurements. Devising and demonstrating a novel quantum optics method for alignment. Introducing a way to describe the past of quantum systems based on the two-state vector formalism and explaining paradoxical quantum phenomena. Providing local description of the Aharonov-Bohm effect and thus opening the way for constructing local quantum theory.

Future directions include: Applying ideas of the two-state vector formalism for constructing devices to move forward the ongoing quantum technology revolution, in particular, by analyzing and continuously monitoring quantum systems. Developing the many-worlds interpretation to make it a consensus among physicists and philosophers. Developing practical key distribution device and searching for new quantum effects leading to supremacy of quantum technology.