Quantum Measurement of Spin Correlations in a Symmetric Many-Body State$\backslash $f1

h $-abstract-$\backslash $pard Continuous (nonprojective) measurement on a quantum system has been employed previously for fast, robust, and high-fidelity quantum state tomography (QST) on qudits [1]. We expand this protocol to many-body systems in order to perform QST on the reduced one-body and two-body density matrices of a symmetric many-body state of multiple qubits. Such QST will characterize the spin correlations in the system. In this protocol, a continuous measurement is done collectively on many copies of the reduced state at the same time, and therefore, while it is weakly perturbative on each copy, yields high signal-to-noise. Simultaneously, we subject the system to an external collective control in order to generate an informationally complete measurement record. We characterize the information-gain measurement disturbance tradeoff in terms of parameters in the problem (number of qubits, control parameters, shot-noise bandwidth, and the measurement strength).$\backslash $pard1] C. Riofr\'{\i}o,, P. S. Jessen, and I. H. Deutsch, ``Quantum tomography of the full hyperfine manifold of atomic spins via continuous measurement on an ensemble'', J. Phys. B 15, 154007 (2011).$\backslash $pard$\backslash $pard$\backslash $pard-/abstract-$\backslash $\tex