Observation of geometric phases for mixed states using NMR interferometry.
Examples of geometric phases abound in many areas of physics. They offer both fundamental insights into many physical phenomena and lead to interesting practical implementations. One of them, as indicated recently, might be an inherently fault-tolerant quantum computation. This, however, requires one to deal with geometric phases in the presence of noise and interactions between different physical subsystems. Despite the wealth of literature on the subject of geometric phases very little is known about this very important case. Here we report the first experimental study of geometric phases for mixed quantum states. We show how different they are from the well-understood, noiseless, pure-state case.
Du
Jiangfeng
J
Structural Research Laboratory, University of Science and Technology of China, Hefei, 230027, People's Republic of China. djf@ustc.edu.cn
Zou
Ping
P
Shi
Mingjun
M
Kwek
Leong Chuan
LC
Pan
Jian-Wei
JW
Oh
C H
CH
Ekert
Artur
A
Oi
Daniel K L
DK
Ericsson
Marie
M