• Corpus ID: 250698753

Measurements conspire nonlocally to restructure critical quantum states

@inproceedings{Garratt2022MeasurementsCN,
  title={Measurements conspire nonlocally to restructure critical quantum states},
  author={Samuel J. Garratt and Zack Weinstein and Ehud Altman},
  year={2022}
}
We study theoretically how local measurements perfomed on critical quantum ground states affect long-distance correlations. These states are highly entangled and feature algebraic correlations between local observables. As a consequence, local measurements can have highly nonlocal effects. Our focus is on Tomonaga-Luttinger liquid (TLL) ground states, a continuous family of critical states in one dimension whose structure is parameterized by a Luttinger parameter K . We show that arbitrarily weak… 

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References

SHOWING 1-10 OF 71 REFERENCES

Long-range entanglement from measuring symmetry-protected topological phases

A fundamental distinction between many-body quantum states are those with shortand longrange entanglement (SRE and LRE). The latter cannot be created by finite-depth circuits, underscoring the

Entanglement Entropy Scaling Transition under Competing Monitoring Protocols.

This work analyzes the competition between two different dissipation channels arising from two incompatible continuous monitoring protocols, and presents a transition for the scaling of the averaged trajectory entanglement entropies, from critical scaling to area-law behavior.

Effective Theory for the Measurement-Induced Phase Transition of Dirac Fermions

A wave function exposed to measurements undergoes pure state dynamics, with deterministic unitary and probabilistic measurement-induced state updates, defining a quantum trajectory. For many-particle

Entanglement Phase Transitions in Measurement-Only Dynamics

Unitary circuits subject to repeated projective measurements can undergo an entanglement transition as a function of the measurement rate. This transition is generally understood in terms of a

Probing sign structure using measurement-induced entanglement

The sign structure of quantum states is closely connected to quantum phases of matter, yet detecting such fine-grained properties of amplitudes is subtle. Here we employ as a diagnostic

Measurement-induced criticality in random quantum circuits

We investigate the critical behavior of the entanglement transition induced by projective measurements in (Haar) random unitary quantum circuits. Using a replica approach, we map the calculation of

Disentangling quantum matter with measurements

Measurements destroy entanglement. Building on ideas used to study `quantum disentangled liquids', we explore the use of this effect to characterize states of matter. We focus on systems with

Measurement-Induced Phase Transitions in the Dynamics of Entanglement

We define dynamical universality classes for many-body systems whose unitary evolution is punctuated by projective measurements. In cases where such measurements occur randomly at a finite rate $p$

Postselection-Free Entanglement Dynamics via Spacetime Duality.

This work proposes a method to sidestep the need to apply postselection on random measurement outcomes in order to repeatedly prepare a given output state in a wide class of nonunitary circuits by taking advantage of spacetime duality.

Probing quantum and thermal noise in an interacting many-body system

The probabilistic character of the measurement process is one of the most puzzling and fascinating aspects of quantum mechanics. In many-body systems quantum-mechanical noise reveals non-local
...