Condensed Matter Seminars

Quantum computers offer exponential speedup over classical computers in solving certain tasks. Superconducting Josephson devices are promising candidates in realizing qubits for quantum computer due to the ease of scaling up. The main challenge of superconducting qubits is decoherence, arising from the coupling between the superconducting qubits and the environment. Here we directly measure the intrawell energy relaxation time au_d between macroscopic quantum levels in the double well potential of a Nb superconducting qubit. The qubit's decoherence time, estimated from au_d, is longer than 20 micro s, indicating a strong potential for quantum computing employing Nb-based superconducting qubits.