A new kind of CNOT-gate implementation for information processing with trapped ions

In this paper, a scheme is presented to implement the 1→2 universal quantum cloning machine (UQCM) with trapped ions. In this way, we also show that quantum information can be directly transferred from one ion to another. The distinct advantage of the scheme lies in the fact that it does not use the vibrational mode as the data bus. The vibrational mode is only virtually excited, which makes our scheme insensitive to heating, provided the system remains in the Lamb–Dicke regime.

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Quantum information processing with trapped ions

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2003.1205 ◽

2003 ◽

Vol 361 (1808) ◽

pp. 1349-1361 ◽

Cited By ~ 84

Author(s):

D. J. Wineland ◽

M. Barrett ◽

J. Britton ◽

J. Chiaverini ◽

B. DeMarco ◽

...

Keyword(s):

Information Processing ◽

Quantum Information ◽

Quantum Information Processing ◽

Trapped Ions

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Stability versus reversibility in information processing

International Journal of Modern Physics Conference Series ◽

10.1142/s2010194514603536 ◽

2014 ◽

Vol 33 ◽

pp. 1460353 ◽

Cited By ~ 7

Author(s):

Robert Alicki

Keyword(s):

Information Processing ◽

Quantum Dynamics ◽

Degrees Of Freedom ◽

Large Scale ◽

Quantum Noise ◽

Quantum Model ◽

Stability Factor ◽

Cnot Gate ◽

Model Stability ◽

Quantum Computations

The paper is motivated by the discussion of feasibility of large scale quantum computations which should incorporate both unitarity of quantum dynamics for information bearing degrees of freedom and stability with respect to environmental noise. The minimal thermodynamic cost of a single CNOT gate, which is equivalent to the minimal cost of a quantum measurement of a binary observable is analyzed using a generic quantum model of one bit memory. For this model stability of memory with respect to thermal and quantum noise and the error of readout can be quantified. One obtains the relations between the minimal work which is invested in a measurement or CNOT gate, the error and the stability factor. The basic formula differs from the standard Landauer one and seems to be much more realistic. The results show the fundamental conflict between stability and irreversibility of information processing. This explains the feasibility of classical stable and scalable information processing performed by irreversible gates and suggests impossibility of large scale quantum computations based on unitary gates.

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