Research interest

Classically, it seems counterintuitive that measurements can drastically alter the overall character of a quantum system, and yet it happens. Many interacting quantum systems are known to exhibit measurement-induced entanglement transition between volume-law and area-law phases. For the transverse Ising chain under a non-probabilistic global measurement protocol, we observe such a transition numerically for small size and show that it also appears in the behaviour of survival probability. Although the entanglement can be computed only numerically for small system-size, we show that the survival probability can be calculated analytically for large system-size. Our main result is that when the system size is large, the transition disappears and there remains only a volume-law phase (and that too, irrespective of the presence of the strength of the transverse field). We also analyse the scaling of the transition point analytically. Our work indicates that the entanglement transition, often observed numerically for small systems, should not be uncritically assumed to exist in the thermodynamic limit.