Instantaneous indirect measurement principle in quantum mechanics
- URL: http://arxiv.org/abs/2207.04761v2
- Date: Thu, 28 Jul 2022 04:12:22 GMT
- Title: Instantaneous indirect measurement principle in quantum mechanics
- Authors: Wangjun Lu, Xingyu Zhang, Lei Shao, Zhucheng Zhang, Jie Chen, Rui
Zhang, Shaojie Xiong, Liyao Zhan, and Xiaoguang Wang
- Abstract summary: We propose a method to obtain the average value of one operator in a certain state by measuring the instantaneous change of the average value of another operator.
For the system to be measured, we find that such measurement neither significantly affects the wave function of the system nor causes wave function collapse of the system.
- Score: 8.626149751795754
- License: http://creativecommons.org/licenses/by/4.0/
- Abstract: In quantum systems, the measurement of operators and the measurement of the
quantum states of the system are very challenging tasks. In this Letter, we
propose a method to obtain the average value of one operator in a certain state
by measuring the instantaneous change of the average value of another operator
with the assistance of a known reference state. We refer to this measurement
method as the instantaneous indirect measurement method. By studying the
application of this method to some typical models, we find that this
measurement can be applied to the measurement of an arbitrary state of a
quantum system. Furthermore, for the system to be measured, we find that such
measurement neither significantly affects the wave function of the system nor
causes wave function collapse of the system. Also, our study shows that when
two independent systems are coupled, the information mapping between them is
done instantaneously. Finally, we discuss applying this measurement method to
the measurement of quantum Fisher information, which quantizes the limited
accuracy of estimating a parameter from a quantum state.
Related papers
- Effect of the readout efficiency of quantum measurement on the system entanglement [44.99833362998488]
We quantify the entanglement for a particle on a 1d quantum random walk under inefficient monitoring.
We find that the system's maximal mean entanglement at the measurement-induced quantum-to-classical crossover is in different ways by the measurement strength and inefficiency.
arXiv Detail & Related papers (2024-02-29T18:10:05Z) - Relational superposition measurements with a material quantum ruler [2.912552849396905]
We introduce a model to describe an extended material quantum system working as a position measurement device.
We show that we can define a quantum measurement procedure corresponding to the "superposition of positions"
The model is fully relational, because the only meaningful variables are the relative positions between the ruler and the system.
arXiv Detail & Related papers (2023-06-01T05:03:21Z) - Quantifying measurement-induced quantum-to-classical crossover using an
open-system entanglement measure [49.1574468325115]
We study the entanglement of a single particle under continuous measurements.
We find that the entanglement at intermediate time scales shows the same qualitative behavior as a function of the measurement strength.
arXiv Detail & Related papers (2023-04-06T09:45:11Z) - 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) - Measurement operator for quantum nondemolition measurements [6.141422382258041]
We derive a measurement operator corresponding to a quantum nondemolition (QND) measurement of an atomic ensemble.
The quantum measurement operator takes the form of a positive operator valued measure (POVM)
arXiv Detail & Related papers (2023-01-14T12:40:50Z) - Quantum Back-action Limits in Dispersively Measured Bose-Einstein
Condensates [0.0]
We theoretically and experimentally characterize quantum back-action in atomic Bose-Einstein condensates interacting with a far-from resonant laser beam.
We experimentally quantify the resulting wavefunction change in terms of the contrast of a Ramsey interferometer.
This result is a necessary precursor for achieving true quantum back-action limited measurements of quantum gases.
arXiv Detail & Related papers (2022-09-09T17:04:36Z) - Quantum state inference from coarse-grained descriptions: analysis and
an application to quantum thermodynamics [101.18253437732933]
We compare the Maximum Entropy Principle method, with the recently proposed Average Assignment Map method.
Despite the fact that the assigned descriptions respect the measured constraints, the descriptions differ in scenarios that go beyond the traditional system-environment structure.
arXiv Detail & Related papers (2022-05-16T19:42:24Z) - Finite resolution ancilla-assisted measurements of quantum work
distributions [77.34726150561087]
We consider an ancilla-assisted protocol measuring the work done on a quantum system driven by a time-dependent Hamiltonian.
We consider system Hamiltonians which both commute and do not commute at different times, finding corrections to fluctuation relations like the Jarzynski equality and the Crooks relation.
arXiv Detail & Related papers (2021-11-30T15:08:25Z) - Observing a Topological Transition in Weak-Measurement-Induced Geometric
Phases [55.41644538483948]
Weak measurements in particular, through their back-action on the system, may enable various levels of coherent control.
We measure the geometric phases induced by sequences of weak measurements and demonstrate a topological transition in the geometric phase controlled by measurement strength.
Our results open new horizons for measurement-enabled quantum control of many-body topological states.
arXiv Detail & Related papers (2021-02-10T19:00:00Z) - Systematic errors in direct state measurements with quantum controlled
measurements [0.0]
We use a quantum controlled measurement framework for measuring quantum states directly.
We numerically investigate the systematic errors, evaluate the confidence region, and investigate the effect of experimental noise.
Our analysis has important applications in direct quantum state tomography.
arXiv Detail & Related papers (2020-02-18T01:40:30Z)
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.