P13 - Photonic Quantum Computing

Philip Walther


Single photons provide unique advantages for quantum information applications due to their robustness, individual addressability and bosonic character. Moreover, the intrinsic mobility of single photons makes them the best quantum information carriers for quantum networks, delegated quantum cloud computing [R13-1] and novel quantum computation schemes such as Boson Sampling and quantum random walks [R13-2].

The long-term goals of our project are the development of quantum photonics technology for (i) secure delegated quantum computing in real-life scenarios and quantum homomorphic encryption schemes that enable a broad class of quantum computation on encrypted data, and (ii) hybrid quantum-classical systems, where classical computation is supported by feasible quantum photonics technology, and (iii) implementing machine learning and random-walk computations using complex integrated network structures, and (iv) demonstrating novel quantum protocols that exploit superimposed orders of gates for outperforming standard, fixed-order schemes.


Subproject Leader: Philip Walther

Co-PIs: Lee Rozema, Michael Trupke

PhD Students: Stella, Joshua Morris, Céline Van Valkenhoef


Integrated-optics heralded controlled-NOT gate for polarization-encoded qubits
J. Zeuner, A.N. Sharma, M. Tillmann, R. Heilmann, M. Gräfe, A. Moqanaki, A. Szameit, P. Walther
npj Quantum Information 4, 13 (2018).

On unitary reconstruction of linear optical networks
M. Tillmann, C. Schmidt, P. Walther
Journal of Optics, 18,  4002 (2016).

Generalized Multiphoton Quantum Interference
M. Tillmann, S.-H. Tan, S.E. Stoeckl, B.C. Sanders, H. de Guise, R. Heilmann, S. Nolte, A. Szameit, P. Walther
Physical Review X 5, 041015 (2015).

For further publications: see here.