# Creating a Superposition of Unknown Quantum States.

@article{Oszmaniec2016CreatingAS, title={Creating a Superposition of Unknown Quantum States.}, author={Michał Oszmaniec and Andrzej Grudka and Michał Horodecki and Antoni W{\'o}jcik}, journal={Physical review letters}, year={2016}, volume={116 11}, pages={ 110403 } }

The superposition principle is one of the landmarks of quantum mechanics. The importance of quantum superpositions provokes questions about the limitations that quantum mechanics itself imposes on the possibility of their generation. In this work, we systematically study the problem of the creation of superpositions of unknown quantum states. First, we prove a no-go theorem that forbids the existence of a universal probabilistic quantum protocol producing a superposition of two unknown quantum…

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## References

SHOWING 1-10 OF 11 REFERENCES

### Quantum computation and quantum information

- PhysicsMathematical Structures in Computer Science
- 2007

This special issue of Mathematical Structures in Computer Science contains several contributions related to the modern field of Quantum Information and Quantum Computing. The first two papers deal…

### Naturwissenschaften 23

- 1
- 1935

### New J

- Phys. 16, 093026
- 2014

### Nature (London) 404

- 164
- 2000

### We decided to use this notation to avoid ambiguity. The relation to the standard notation used in quantum mechanics is simply given by P ψ = |ψ ψ|

### Science 282

- 1686
- 1998

### Optical Coherence and Quantum Optics (Cambridge

- 1995

### Nature (London) 299

- 802
- 1982