TY - JOUR
T1 - Contractive states and the standard quantum limit for monitoring free-mass positions
AU - Yuen, Horace Pak-Hong
PY - 1983/1/1
Y1 - 1983/1/1
N2 - The familiar minimum-uncertainty wave packets for masses are generalized in analogy with the two-photon coherent states of the radiation field. The free evolution of a subclass of these states, the contractive states, leads to a narrowing of the position uncertainty in contrast with the usual minimum-uncertainty wave packets. As a consequence the standard quantum limit for monitoring the positions of a free mass can be breached. Further implications on quantum nondemolition measurements are discussed.
AB - The familiar minimum-uncertainty wave packets for masses are generalized in analogy with the two-photon coherent states of the radiation field. The free evolution of a subclass of these states, the contractive states, leads to a narrowing of the position uncertainty in contrast with the usual minimum-uncertainty wave packets. As a consequence the standard quantum limit for monitoring the positions of a free mass can be breached. Further implications on quantum nondemolition measurements are discussed.
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U2 - 10.1103/PhysRevLett.51.719
DO - 10.1103/PhysRevLett.51.719
M3 - Article
AN - SCOPUS:0000106138
VL - 51
SP - 719
EP - 722
JO - Physical Review Letters
JF - Physical Review Letters
SN - 0031-9007
IS - 9
ER -