  Given a quantum state with an unknown parameter, the Quantum Fisher
Information (QFI) is a measure of the amount of information that an observable
can extract about the parameter. QFI also quantifies the maximum achievable
precision in estimating the parameter with a given amount of resource via an
inequality known as quantum Cramer-Rao bound. In this work, we describe a
protocol to amplify QFI of a single target qubit precorrelated with a set of
ancillary qubits. A single quadrature measurement of only ancillary qubits
suffices to perform the complete quantum state tomography (QST) of the target
qubit. We experimentally demonstrate this protocol using an NMR system
consisting of a $^{13}$C nuclear spin as the target qubit and three $^1$H
nuclear spins as ancillary qubits. We prepare the target qubit in various
initial states, perform QST, and estimate the amplification of QFI in each
case. We also show that the QFI-amplification scales linearly with the number
of ancillary qubits and quadratically with their purity.
