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I have just started self-learning quantum information theory, and have a sub-trivial question: what is the difference between that field of study and quantum computation?

I have some understanding that quantum information theory studies the way in which quantum systems can hold information, and that quantum computation (from what I can tell) seems to be more about studying how logic gates can manipulate that information.

I have seen several textbooks with names like "Quantum Computation and Quantum Information Theory", which definitely suggests that these are not the same field, but I have found it tough to find a definitive definition of both of them by the same author. Indeed, the textbook I am currently reading does define information theory in great detail, but doesn't define quantum computation theory (as a subject). This author then goes on to tell us how useful information theory is if we want to make a quantum computer. This suggests to me that they are the same field...maybe.

Are quantum information and quantum computation synonymous? If not, what are the differences between these two fields.

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closed as primarily opinion-based by Norbert Schuch, Sebastian Riese, Gert, ACuriousMind, David Z Mar 6 '16 at 11:32

Many good questions generate some degree of opinion based on expert experience, but answers to this question will tend to be almost entirely based on opinions, rather than facts, references, or specific expertise. If this question can be reworded to fit the rules in the help center, please edit the question.

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    $\begingroup$ This is really mostly an opinion-based question, and depends very much on the context and who you ask. Generally, I would say QC is concerned with solving computational problems using quantum mechanical systems, while QI is concerned with the information content and information processing (communication etc.) with QM systems, but clearly the boundary is fluent. QI is also sometimes being used as a more general term, encomassing both QI and QC. $\endgroup$ – Norbert Schuch Mar 4 '16 at 16:23
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Compare the general theory of information storage and transfer with that of computing: computation makes use of both of these fields. Computation transforms information.

So the two fields oft times intersect, but they are as different as calculators and books, or as similar as an abacus and a telegram.

Claude Shannon developed the classical theory of information transfer for both perfect and imperfect communications channels; Alan Turing developed the Turing machine model of computation, and proved that any type of information processing system could be be implemented by an ideal Turing machine.

Today the two fields are very intertwined, but the foundations are independent. Classical or quantum, the basic concepts are similar, and so are the differences.

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