Untitled

Vaidman, Lev

doi:10.1023/a:1018826607583

Cited by 16 publications

(8 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We are thus certain to find the system on path 3. This apparent paradox has triggered vivid discussions on counterfactuals in pre and post-selected systems [17,[22][23][24][25]. We will just note here that both properties following from P (a 1 ) = 1 and P (a 3 ) = 1 are well-defined, but each in its own configuration, involving different measurements and experimental arrangements.…”

Section: E Properties In Pre and Post-selected Systems: The Abl Rulementioning

confidence: 99%

Weak Values and Quantum Properties

Matzkin

2019

Found Phys

View full text Add to dashboard Cite

We investigate in this work the meaning of weak values through the prism of property ascription in quantum systems. Indeed, the weak measurements framework contains only ingredients of the standard quantum formalism, and as such weak measurements are from a technical point of view uncontroversial. However attempting to describe properties of quantum systems through weak values -the output of weak measurements -goes beyond the usual interpretation of quantum mechanics, that relies on eigenvalues. We first recall the usual form of property ascription, based on the eigenstate-eigenvalue link and the existence of "elements of reality". We then describe against this backdrop the different meanings that have been given to weak values. We finally argue that weak values can be related to a specific form of property ascription, weaker than the eigenvalues case but still relevant to a partial description of a quantum system.

show abstract

Section: E Properties In Pre and Post-selected Systems: The Abl Rulementioning

confidence: 99%

Weak Values and Quantum Properties

Matzkin

2019

Found Phys

View full text Add to dashboard Cite

show abstract

“…(69) is not valid and conclude that the ABL formula is not applicable to this example and therefore it is not applicable in general. One us (LV) has argued [106,107,21] that the error in calculating equality (69) does not arise from the conditional probabilities given by the ABL formula, but from the calculation of the probabilities Prob(1 f ) and Prob(2 f ) of the final measurement. In all three alleged proofs the probabilities Prob(1 f ) and Prob(2 f ) were calculated on the assumption that no measurement took place at time t. Clearly, one cannot make this assumption here since then the discussion about the probability of the result of the measurement at time t is meaningless.…”

Section: Counterfactual Interpretation Of the Abl Rulementioning

confidence: 99%

“…The measurement of C constrains the possible states immediately after t to the eigenstates of C. Therefore, if in the actual world the state immediately after t is not an eigenstate of C, no counterfactual world with the same state exists. Moreover, there is the same problem with the backward evolving quantum state (the concept which does not exist in the standard approach) in the period of time before t. This difficulty can be solved by adopting the following definition of the closest world [107]:…”

Section: Counterfactual Interpretation Of the Abl Rulementioning

confidence: 99%

The Two-State Vector Formalism: An Updated Review

Aharonov

Vaidman

Time in Quantum Mechanics

Self Cite

174

236

View full text Add to dashboard Cite

In this paper we present the two-state vector formalism of quantum mechanics. It is a time-symmetrized approach to standard quantum theory particularly helpful for the analysis of experiments performed on pre-and post-selected ensembles. Several peculiar effects which naturally arise in this approach are considered. In particular, the concept of "weak measurements" (standard measurements with weakening of the interaction) is discussed in depth revealing a very unusual but consistent picture. Also, a design of a gedanken experiment which implements a kind of quantum "time machine" is described. The issue of time-symmetry in the context of the two-state vector formalism is clarified.

show abstract

“…One us (LV) has argued [39,40,16] that the error in calculating equality (13.69) does not arise from the conditional probabilities given by the ABL formula, but from the calculation of the probabilities Prob(1 f ) and Prob(2 f ) of the final measurement. In all three alleged proofs the probabilities Prob(1 f ) and Prob(2 f ) were calculated on the assumption that no measurement took place at time t. Clearly, one cannot make this assumption here since then the discussion about the probability of the result of the measurement at time t is meaningless.…”

Section: Counterfactual Interpretation Of the Abl Rulementioning

confidence: 99%

Section: Counterfactual Interpretation Of the Abl Rulementioning

confidence: 99%

The Two-State Vector Formalism of Quantum Mechanics

Aharonov

Vaidman

Time in Quantum Mechanics

Self Cite

129

View full text Add to dashboard Cite

We present the two-state vector formalism of quantum mechanics. It is a timesymmetrized approach to standard quantum theory particularly helpful for the analysis of experiments performed on pre-and post-selected ensembles. Several peculiar effects which naturally arise in this approach are considered. In particular, the concept of "weak measurements" (standard measurements with weakening of the interaction) is discussed in depth revealing a very unusual but consistent picture. Also, a design of a gedanken experiment which implements a kind of quantum "time machine" is described. The issue of time-symmetry in the context of the two-state vector formalism is clarified. Descriptions of Quantum Systems The Quantum StateIn the standard quantum mechanics, a system at a given time t is described completely by a quantum state |Ψ , (13.1) defined by the results of measurements performed on the system in the past relative to the time t. (It might be that the system at time t is not described by a pure quantum state, but by a mixed state (density matrix). However, we can always assume that there is a composite system including this system which is in a pure state.) The status of a quantum state is controversial: there are many papers on reality of a quantum state and numerous interpretations of this "reality". However, it is non-controversial to say that the quantum state yields maximal information about how this system can affect other systems (in particular, measuring devices) interacting with it at time t. Of course, the results of all measurements in the past, or just the results of the last complete measurement, also have this information, but these results include other facts too, so the quantum state is the most concise information about how the quantum system can affect other systems at time t.

show abstract

Untitled

Cited by 16 publications

References 52 publications

Weak Values and Quantum Properties

Weak Values and Quantum Properties

The Two-State Vector Formalism: An Updated Review

The Two-State Vector Formalism of Quantum Mechanics

Contact Info

Product

Resources

About