Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Physical Review A

Proposal for reversing the weak measurement with arbitrary maximum photon number

Xiaodong Zeng, M. Al-Amri, Shi‐Yao Zhu, Muhammad Suhail Zubairy

Published May 20, 2016• 3 citations
Publisher

Abstract

We present a proposal for reversing the weak (partial-collapse) quantum measurement on a cavity field with arbitrary maximum photon number. We start by putting forth a protocol to realize quantum phase gates between the cavity field and an ancilla qubit. Afterward, adopting these phase gates and some other quantum gates, we can determine the reversal of the cavity state just by observing the ancilla qubit. Compared to previous proposals, our proposal does not need any other weak measurement and can save reversal time, which is significantly important in quantum informatics and quantum computation.

DOI
10.1103/physreva.93.053826

Related papers

Reversing the weak measurement on a qubit

M. Al-Amri, Marlan O. Scully, Muhammad Suhail Zubairy

We propose a protocol for the reversal of a weak measurement on a qubit and discuss a possible experimental scheme for the state protection in a cavity QED system. Unlike previous methods for the reversal of weak measurement, the proposed scheme does not require another weak measurement in the reversal process and therefore can be accomplished in a small time. The present scheme is based on repeated applications of Hadamard and CNOT gates.

Journal of Physics B Atomic Molecular and Optical Physics•Jul 29, 2011•23 citations

Reversing the weak quantum measurement for a photonic qubit

Yong‐Su Kim, Young‐Wook Cho, Young-Sik Ra +1 more

We demonstrate the conditional reversal of a weak (partial-collapse) quantum measurement on a photonic qubit. The weak quantum measurement causes a nonunitary transformation of a qubit which is subsequently reversed to the original state after a successful reversing operation. Both the weak measurement and the reversal operation are implemented linear optically. The state recovery fidelity, determined by quantum process tomography, is shown to be over 94% for partial-collapse strength up to 0.9. We also experimentally study information gain due to the weak measurement and discuss the role of the reversing operation as an information erasure.

arXiv:0903.3077•Optics Express•Jun 30, 2009•207 citations

Reversing the weak measurement of an arbitrary field with finite photon number

Qingqing Sun, M. Al-Amri, Muhammad Suhail Zubairy

For an arbitrary field with finite photon number inside a leaky cavity, we show that the null-result measurement can be conditionally reversed, using either multiple atoms or a multilevel atom. Even with photons detected, a certain class of fields can still be probabilistically recovered. The state protection probability in such a system can be significantly high.

Physical Review A•Sep 25, 2009•95 citations

Reversing the Weak Quantum Measurement for a Photonic Qubit

Yong‐Su Kim, Young‐Wook Cho, Young-Sik Ra +1 more

We demonstrate the conditional reversal of a weak quantum measurement on a photonic qubit. The state recovery fidelity, determined by quantum process tomography, is shown to be over 94% for partial-collapse strength up to 0.9. We also experimentally study information gain due to the weak measurement and discuss the role of the reversing operation as an information erasure.

Conference on Lasers and Electro-Optics•Jan 1, 2010•10 citations

Quantum state protection in finite-temperature environment via quantum gates

Xiaodong Zeng, Guo-Qin Ge, Muhammad Suhail Zubairy

We propose a protocol to protect the quantum states and entanglements from finite-temperature thermal noise via quantum gates. Compared to the common protocols protecting the quantum states and entanglements by using weak measurements and their reversals, no time-consuming weak measurements are needed in the present protocol and consequently, it is much faster. We also discuss the possible implementation of the protocol in cavity QED system.

Optics Express•Aug 27, 2019•4 citations

Decomposing qubit positive-operator-valued measurements into continuous destructive weak measurements

Yi‐Hsiang Chen, Todd A. Brun

It has been shown that any generalized measurement can be decomposed into a sequence of weak measurements corresponding to a stochastic process. However, the weak measurements may require almost arbitrary unitaries, which are unlikely to be realized by any real measurement device. Furthermore, many measurement processes are destructive, like photon counting procedures that terminate once all photons are consumed. One cannot expect to have full control of the evolution of a state under such destructive measurements, and the possible unitaries allow only a limited set of weak measurements. In this paper, we consider a qubit model of destructive weak measurements, which is a toy version of an optical cavity, in which the state of an electromagnetic field mode inside the cavity leaks out and is measured destructively while the vacuum state $|0\ensuremath{\rangle}$ leaks into the cavity. At long times, the state of the qubit inevitably evolves to be $|0\ensuremath{\rangle}$, and the only available control is the choice of measurement on the external ancilla system. Surprisingly, this very limited model can still perform an arbitrary projective measurement on the qubit in any basis, where the probability of getting an outcome satisfies the usual Born rule. Combining this method with probabilistic postprocessing, the result can be extended to any generalized measurement with commuting positive-operator-valued measurement (POVM) elements. This implies, among other results, that any two-outcome POVM on a qubit can be decomposed into a sequence of destructive weak measurements by this restricted measurement device.

arXiv:1804.03354•Physical Review A•Dec 18, 2018•2 citations
We present a proposal for reversing the weak (partial-collapse) quantum measurement on a cavity field with arbitrary maximum photon number. We start by putting forth a protocol to realize quantum phase gates between the cavity field and an ancilla qubit. Afterward, adopting these phase gates and some other quantum gates, we can determine the reversal of the cavity state just by observing the ancilla qubit. Compared to previous proposals, our proposal does not need any other weak measurement and can save reversal time, which is significantly important in quantum informatics and quantum computation.
We demonstrate the conditional reversal of a weak (partial-collapse) quantum measurement on a photonic qubit. The weak quantum measurement causes a nonunitary transformation of a qubit which is subsequently reversed to the original state after a successful reversing operation. Both the weak measurement and the reversal operation are implemented linear optically. The state recovery fidelity, determined by quantum process tomography, is shown to be over 94% for partial-collapse strength up to 0.9. We also experimentally study information gain due to the weak measurement and discuss the role of the reversing operation as an information erasure.
It has been shown that any generalized measurement can be decomposed into a sequence of weak measurements corresponding to a stochastic process. However, the weak measurements may require almost arbitrary unitaries, which are unlikely to be realized by any real measurement device. Furthermore, many measurement processes are destructive, like photon counting procedures that terminate once all photons are consumed. One cannot expect to have full control of the evolution of a state under such destructive measurements, and the possible unitaries allow only a limited set of weak measurements. In this paper, we consider a qubit model of destructive weak measurements, which is a toy version of an optical cavity, in which the state of an electromagnetic field mode inside the cavity leaks out and is measured destructively while the vacuum state $|0\ensuremath{\rangle}$ leaks into the cavity. At long times, the state of the qubit inevitably evolves to be $|0\ensuremath{\rangle}$, and the only available control is the choice of measurement on the external ancilla system. Surprisingly, this very limited model can still perform an arbitrary projective measurement on the qubit in any basis, where the probability of getting an outcome satisfies the usual Born rule. Combining this method with probabilistic postprocessing, the result can be extended to any generalized measurement with commuting positive-operator-valued measurement (POVM) elements. This implies, among other results, that any two-outcome POVM on a qubit can be decomposed into a sequence of destructive weak measurements by this restricted measurement device.