# The limits of counterfactual computation

@article{Mitchison2006TheLO, title={The limits of counterfactual computation}, author={G. Mitchison and R. Jozsa}, journal={arXiv: Quantum Physics}, year={2006} }

We show that the protocol recently proposed by Hosten et al. does not allow all possible results of a computation to be obtained counterfactually, as was claimed. It only gives a counterfactual outcome for one of the computer outputs. However, we confirm the observation that the protocol gives some protection against decoherence. In some situations, though, it may be more effective simply to run the computer several times.

#### 11 Citations

Impossibility of the counterfactual computation for all possible outcomes.

- Computer Science, Physics
- Physical review letters
- 2007

It is argued that the method does not provide counterfactual computation for all possible outcomes, and involves a novel paradoxical feature of pre- and postselected quantum particles. Expand

Counterfactual computation revisited

- Mathematics, Physics
- 2006

Mitchison and Jozsa recently suggested that the "chained-Zeno" counterfactual computation protocol recently proposed by Hosten et al. is counterfactual for only one output of the computer. This claim… Expand

Weak Measurements and Counterfactual Computation

- Physics, Mathematics
- 2006

Vaidman, in a recent article adopts the method of 'quantum weak measurements in pre- and postselected ensembles' to ascertain whether or not the chained-Zeno counterfactual computation scheme… Expand

Counterfactual quantum computation

- Physics
- 2005 Quantum Electronics and Laser Science Conference
- 2005

We present the first demonstration of Jozsa's "counterfactual computation", using an optical Grover's search algorithm. We put the algorithm in a superposition of "running" and "not-running",… Expand

A dynamical quantum Cheshire Cat effect and implications for counterfactual communication

- Medicine
- Nature communications
- 2021

A type of dynamic effect is reported that is at the core of the so called "counterfactual computation" and especially " counterfactual communication" quantum effects that have generated a lot of interest recently, and generalizes the quantum Cheshire Cat effect to dynamical settings. Expand

Upper Bounds on Quantum Query Complexity Inspired by the Elitzur-Vaidman Bomb Tester

- Mathematics, Computer Science
- Computational Complexity Conference
- 2015

A method of finding bomb query algorithms from classical algorithms, which then provide nonconstructive upper bounds on $Q(f)=\Theta(\sqrt{B(f)})$ is given, which gives a new method to upper bound the quantum query complexity. Expand

Topics in quantum algorithms : adiabatic algorithm, quantum money, and bomb query complexity

- Mathematics
- 2015

by Han-Hsuan Lin Submitted to the Department of Physics on May 22, 2015, in partial fulfillment of the requirements for the degree of Ph.D. in Physics In this thesis, I present three results on… Expand

Atomic quantum metrology with narrowband entangled and squeezed states of light

- Physics
- 2012

The use of light, especially of laser light, is in many cases the most sensitive way to perform measurements. However, the highest sensitivity that can be achieved with laser light as probe is… Expand

Interaction-free measurements and counterfactual computation in IBM quantum computers

- Computer Science, Physics
- Quantum Inf. Process.
- 2021

This work implements interaction-free measurements and counterfactual computations in actual 5-qubit, 15-qu bit and 20-qu Bit IBM quantum computers by means of simple quantum circuits and implements a simple error mitigation procedure. Expand

Upper Bounds on Quantum Query Complexity Inspired by the Elitzur--Vaidman Bomb Tester

- Mathematics, Computer Science
- Theory Comput.
- 2016

A method of finding bomb query algorithms from classical algorithms, which then provide non-constructive upper bounds on Q(f) = Θ(B(f)). Expand