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تسجيل مستخدم جديدReduced fidelity susceptibility and its finite-size scaling behaviors
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We derive a general formula of the reduced fidelity susceptibility when the reduced density matrix is $2times2$ block-diagonal. By using this result and the continuous unitary transformations, we study finite-size scaling of the reduced fidelity susceptibility in the Lipkin-Meshkov-Glick Model. It is found that it can be used to characterize quantum phase transitions, implying that we can extract information of quantum phase transitions only from the fidelity of a subsystem, which is of practical meaning in experiments.
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