Universal Effectiveness of High-Depth Circuits in Variational Eigenproblems

  title={Universal Effectiveness of High-Depth Circuits in Variational Eigenproblems},
  author={Joonho Kim and Jaedeok Kim and Dario Rosa},
We explore the effectiveness of high-depth, noiseless, parameteric quantum circuits by challenging their capability to simulate the ground states of quantum many-body Hamiltonians. Even a generic layered circuit Ansatz can approximate the ground state with high precision, as long as the circuit depth exceeds a certain threshold level that exponentially scales with the number of qubits, despite the abundance of the barren plateaus. This success is due to the fact that the energy landscape in the… 
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