# Thoughts in coding large and repetitive/non-repetitive quantum circuits?

Just out of curiosity, are there advances or directions on how to write a program (e.g. in qiskit) for a large number of qubits? Assuming that the number of gates that can be applied can be "arbitrary" long along with the coherences, how would one code a circuit for maybe $$2^{50}$$ spins?*

Obviously if the circuit is a bit "repetitive", one can store the "base" circuit only once and applied as many times as needed. But right now does it exist already a tool for such cases? What will happen in the future if the code is fairly complex with few repetitions?

*There are considerable more information in a circuit code that in just the lists of 1 and 0's of binary data...

• I seriously doubt qiskit, or any other python framework, can handle constructing a circuit over $2^{50}$ qubits. At some point you have to actually run it, which is going to involve iterating over all of its gates, and there are too many. You'd need a distributed system, like a supercomputer or a cluster, and you'd need to write the program in a fast language;not python. Jul 20 at 1:19
• By fast you mean not interpreted but compiled? Jul 20 at 13:46
• Yes you probably want a compiled language. You probably also want a team of a hundred people working for a decade on the design of this thing. (It's not literally impossible for one person to design it but they'd have to leave a lot of waste in the system compared to what is possible.) 2^50 is an insanely ambitious number of qubits to use effectively. Jul 20 at 18:24