TY  - JOUR
A1  - Jechow, Andreas
A1  - Norton, B. G.
A1  - Händel, S.
A1  - Blums, V.
A1  - Streed, E. W.
A1  - Kielpinski, D.
T1  - Controllable optical phase shift over one radian from a single isolated atom
JF  - Physical review letters
N2  - Fundamental optics such as lenses and prisms work by applying phase shifts of several radians to incoming light, and rapid control of such phase shifts is crucial to telecommunications. However, large, controllable optical phase shifts have remained elusive for isolated quantum systems. We have used a single trapped atomic ion to induce and measure a large optical phase shift of 1.3 +/- 0.1 radians in light scattered by the atom. Spatial interferometry between the scattered light and unscattered illumination light enables us to isolate the phase shift in the scattered component. The phase shift achieves the maximum value allowed by atomic theory over the accessible range of laser frequencies, pointing out new opportunities in microscopy and nanophotonics. Single-atom phase shifts of this magnitude open up new quantum information protocols, in particular long-range quantum phase-shift-keying cryptography. DOI: 10.1103/PhysRevLett.110.113605
Y1  - 2013
U6  - https://doi.org/10.1103/PhysRevLett.110.113605
SN  - 0031-9007
VL  - 110
IS  - 11
PB  - American Physical Society
CY  - College Park
ER  -