Thermal States as Universal Resources for Quantum Computation with Always-On Interactions
Ying Li, Dan E. Browne, L. C. Kwek, Robert Raussendorf, Tzu-Chieh Wei · Physical Review Letters · 2011
Measurement-based quantum computation utilizes an initial entangled resource state and proceeds with subsequent single-qubit measurements. It is implicitly assumed that the interactions between qubits can be switched off so that the dynamics of the measured qubits do not affect the computation. By proposing a model spin Hamiltonian, we demonstrate that measurement-based quantum computation can be achieved on a thermal state with always-on interactions. Moreover, computational errors induced by thermal fluctuations can be corrected and thus the computation can be executed fault tolerantly if the temperature is below a threshold value.