Abstract: A system for quantum state transfer and entanglement generation includes a quantum system including a plurality of qubits, a processor, and a memory. The memory includes instructions stored thereon, which, when executed by the processor, cause the quantum system to: access a signal of the quantum system; encode unknown coefficients in one qubit of the plurality of qubits; initialize each of the remaining qubits of the plurality of qubits in state |0; group the plurality of qubits into a plurality of subsystems; in each of the plurality of subsystems: encode quantum information into Greenberger-Horne-Zeilinger-like (GHZ-like) states using nearest-neighbor interactions; and apply a generalized controlled-phase gate between the plurality of subsystems to merge the GHZ-like states into an entangled state between of the plurality of subsystems.

Abstract: A method for quantum state transfer includes iteratively expanding an initial quantum state from an initial qudit, of a plurality of qudits, over a sequence of expanding domains. For each iteration, a quantum circuit is applied to the qudits belonging to a respective domain of the sequence. The quantum circuit transforms the qudits of the respective domain into an intermediate quantum state that includes a W state formed with the qudits of the respective domain. The last iteration generates a maximally expanded state. The method may also include iteratively compressing the maximally expanded state according to a sequence of contacting domains. After compressing, a final qudit, of the plurality of qudits, is in a final quantum state that approximates the initial quantum state.