Measurement-induced entanglement transitions in many-body localized
systems
- URL: http://arxiv.org/abs/2005.13603v1
- Date: Wed, 27 May 2020 19:26:12 GMT
- Title: Measurement-induced entanglement transitions in many-body localized
systems
- Authors: Oliver Lunt, Arijeet Pal
- Abstract summary: We investigate measurement-induced entanglement transitions in a system where the underlying unitary dynamics are many-body localized (MBL)
This work further demonstrates how the nature of the measurement-induced entanglement transition depends on the scrambling nature of the underlying unitary dynamics.
This leads to further questions on the control and simulation of entangled quantum states by measurements in open quantum systems.
- Score: 0.0
- License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
- Abstract: The resilience of quantum entanglement to a classicality-inducing environment
is tied to fundamental aspects of quantum many-body systems. The dynamics of
entanglement has recently been studied in the context of measurement-induced
entanglement transitions, where the steady-state entanglement collapses from a
volume-law to an area-law at a critical measurement probability $p_{c}$.
Interestingly, there is a distinction in the value of $p_{c}$ depending on how
well the underlying unitary dynamics scramble quantum information. For strongly
chaotic systems, $p_{c} > 0$, whereas for weakly chaotic systems, such as
integrable models, $p_{c} = 0$. In this work, we investigate these
measurement-induced entanglement transitions in a system where the underlying
unitary dynamics are many-body localized (MBL). We demonstrate that the
emergent integrability in an MBL system implies a qualitative difference in the
nature of the measurement-induced transition depending on the measurement
basis, with $p_{c} > 0$ when the measurement basis is scrambled and $p_{c} = 0$
when it is not. This feature is not found in Haar-random circuit models, where
all local operators are scrambled in time. When the transition occurs at $p_{c}
> 0$, we use finite-size scaling to obtain the critical exponent $\nu =
1.3(2)$, close to the value for 2+0D percolation. We also find a dynamical
critical exponent of $z = 0.98(4)$ and logarithmic scaling of the R\'{e}nyi
entropies at criticality, suggesting an underlying conformal symmetry at the
critical point. This work further demonstrates how the nature of the
measurement-induced entanglement transition depends on the scrambling nature of
the underlying unitary dynamics. This leads to further questions on the control
and simulation of entangled quantum states by measurements in open quantum
systems.
Related papers
- Driven Critical Dynamics in Measurement-induced Phase Transitions [3.1009752388717127]
We generalize the Kibble-Zurek driven critical dynamics that has achieved great success in traditional quantum and classical phase transitions to MIPT.
We find that the driven dynamics from the volume-law phase violates the adiabatic-impulse scenario of the KZ mechanism.
We bring a new fundamental perspective into MIPT that can be detected in fast-developing quantum computers.
arXiv Detail & Related papers (2024-11-11T01:08:14Z) - Noise-induced phase transitions in hybrid quantum circuits [3.625262223613696]
In this work, we investigate the effects of quantum noises with size-dependent probabilities $q=p/Lalpha$ where $alpha$ represents the scaling exponent.
We have identified a noise-induced entanglement phase transition from a volume law to a power (area) law in the presence (absence) of measurements.
This unified picture further deepens the understanding of the connection between entanglement behavior and the capacity of information protection.
arXiv Detail & Related papers (2024-01-30T00:03:56Z) - Entanglement phase transition due to reciprocity breaking without
measurement or post-selection [59.63862802533879]
EPT occurs for a system undergoing purely unitary evolution.
We analytically derive the entanglement entropy out of and at the critical point for the $l=1$ and $l/N ll 1$ case.
arXiv Detail & Related papers (2023-08-28T14:28:59Z) - Evolution of many-body systems under ancilla quantum measurements [58.720142291102135]
We study the concept of implementing quantum measurements by coupling a many-body lattice system to an ancillary degree of freedom.
We find evidence of a disentangling-entangling measurement-induced transition as was previously observed in more abstract models.
arXiv Detail & Related papers (2023-03-13T13:06:40Z) - Universality of critical dynamics with finite entanglement [68.8204255655161]
We study how low-energy dynamics of quantum systems near criticality are modified by finite entanglement.
Our result establishes the precise role played by entanglement in time-dependent critical phenomena.
arXiv Detail & Related papers (2023-01-23T19:23:54Z) - Geometric phases along quantum trajectories [58.720142291102135]
We study the distribution function of geometric phases in monitored quantum systems.
For the single trajectory exhibiting no quantum jumps, a topological transition in the phase acquired after a cycle.
For the same parameters, the density matrix does not show any interference.
arXiv Detail & Related papers (2023-01-10T22:05:18Z) - Full counting statistics as probe of measurement-induced transitions in
the quantum Ising chain [62.997667081978825]
We show that local projective measurements induce a modification of the out-of-equilibrium probability distribution function of the local magnetization.
In particular we describe how the probability distribution of the former shows different behaviour in the area-law and volume-law regimes.
arXiv Detail & Related papers (2022-12-19T12:34:37Z) - Universal KPZ scaling in noisy hybrid quantum circuits [2.103498641058344]
Measurement-induced phase transitions (MIPT) have attracted increasing attention due to the rich phenomenology of entanglement structures.
In this Letter, we investigate the effect of quantum noise modeled by reset quantum channel acting on each site with probability $q$ on MIPT.
arXiv Detail & Related papers (2022-12-07T19:01:04Z) - Linear Response for pseudo-Hermitian Hamiltonian Systems: Application to
PT-Symmetric Qubits [0.0]
We develop the linear response theory formulation suitable for application to various pHH systems.
We apply our results to two textitPT-symmetric non-Hermitian quantum systems.
arXiv Detail & Related papers (2022-06-18T10:05:30Z) - Decoherent Quench Dynamics across Quantum Phase Transitions [0.0]
We formulate decoherent dynamics induced by continuous quantum non-demolition measurements of the instantaneous Hamiltonian.
We generalize the well-studied universal Kibble-Zurek behavior for linear temporal drive across the critical point.
We show that the freeze-out time scale can be probed from the relaxation of the Hall conductivity.
arXiv Detail & Related papers (2021-03-14T23:43:55Z) - Quantum Zeno effect appears in stages [64.41511459132334]
In the quantum Zeno effect, quantum measurements can block the coherent oscillation of a two level system by freezing its state to one of the measurement eigenstates.
We show that the onset of the Zeno regime is marked by a $textitcascade of transitions$ in the system dynamics as the measurement strength is increased.
arXiv Detail & Related papers (2020-03-23T18:17:36Z)
This list is automatically generated from the titles and abstracts of the papers in this site.
This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.