Digital-Analog Quantum Computation and Simulation

Digital-analog quantum computation is an alternative universal quantum computing paradigm which makes use of the natural (analog) interaction Hamiltonian between qubits as an entangling resource combined with fast single-qubit rotations (digital steps). It is a near-term solution to the limitations of NISQ devices which has shown higher resilience against error noises and better scalability perspectives. Therefore, it is possible to adapt and engineer new quantum algorithms which avoid the noise associated to the two-qubit gates in the digital paradigm. Here, we will introduce the digital-analog paradigm and show its university in Hamiltonian simulations. Additionally, we will see how quantum algorithms can be adapted to this paradigm, in particular, the quantum Fourier transform and the Harrow-Hassidim-Lloyd. This will show very helpful to propose co-designed quantum processors to implement them efficiently. Finally, we will analyze its behavior under sensible noise sources by comparing its performance and scalability against the fully digital one.