On-chip coherent conversion of photonic quantum entanglement between different degrees of freedom.
In the quantum world, a single particle can have various degrees of freedom to encode quantum information. Controlling multiple degrees of freedom simultaneously is necessary to describe a particle fully and, therefore, to use it more efficiently. Here we introduce the transverse waveguide-mode degree of freedom to quantum photonic integrated circuits, and demonstrate the coherent conversion of a photonic quantum state between path, polarization and transverse waveguide-mode degrees of freedom on a single chip. The preservation of quantum coherence in these conversion processes is proven by single-photon and two-photon quantum interference using a fibre beam splitter or on-chip beam splitters. These results provide us with the ability to control and convert multiple degrees of freedom of photons for quantum photonic integrated circuit-based quantum information process.
Key Laboratory of Quantum Information, University of Science and Technology of China, CAS, Hefei 230026, China.|Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China.
Lan-Tian
LT
Feng
State Key Laboratory for Modern Optical Instrumentation, Centre for Optical and Electromagnetic Research, Zhejiang Provincial Key Laboratory for Sensing Technologies, Zhejiang University, Zijingang Campus, Hangzhou 310058, China.
Ming
M
Zhang
Key Laboratory of Quantum Information, University of Science and Technology of China, CAS, Hefei 230026, China.|Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China.
Zhi-Yuan
ZY
Zhou
Key Laboratory of Quantum Information, University of Science and Technology of China, CAS, Hefei 230026, China.|Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China.
Ming
M
Li
Key Laboratory of Quantum Information, University of Science and Technology of China, CAS, Hefei 230026, China.|Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China.
Xiao
X
Xiong
Key Laboratory of Quantum Information, University of Science and Technology of China, CAS, Hefei 230026, China.|Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China.
Le
L
Yu
Key Laboratory of Quantum Information, University of Science and Technology of China, CAS, Hefei 230026, China.|Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China.
Bao-Sen
BS
Shi
Key Laboratory of Quantum Information, University of Science and Technology of China, CAS, Hefei 230026, China.|Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China.
Guo-Ping
GP
Guo
State Key Laboratory for Modern Optical Instrumentation, Centre for Optical and Electromagnetic Research, Zhejiang Provincial Key Laboratory for Sensing Technologies, Zhejiang University, Zijingang Campus, Hangzhou 310058, China.
Dao-Xin
DX
Dai
Key Laboratory of Quantum Information, University of Science and Technology of China, CAS, Hefei 230026, China.|Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China.
Xi-Feng
XF
Ren
Key Laboratory of Quantum Information, University of Science and Technology of China, CAS, Hefei 230026, China.|Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China.
Guang-Can
GC
Guo