Quantum Computation in Time Domain
Warit Asavanant, Akira Furusawa · 2022
Optical systems have been long considered to be appropriate for tasks in quantum communications but not quantum computation. This is because the optical systems are “flying qubits” that need actual physical circuits to implement quantum computation, limiting their scalability. In this chapter, we explain a methodology that does not only overcome this limitation but is also one of the currently most promising methods in terms of scalability: time-domain quantum computation. In this method, quantum states are encoded in a localized temporal wave packet. These wave packets can be multiplexed in time, allowing the generation of large-scale cluster states and multi-step quantum operations using only minimal physical resources. We explain basic ideas of quantum computation in the time domain and show several experimental examples.