Superconducting quantum bits with artificial damping tackle the many body problem
Audrey Cottet · npj Quantum Information · 2019
Circuit QED represents one of the most advanced architectures in the race for a quantum computer. Its elementary building blocks, the superconducting quantum bits and microwave cavities, play the role of nearly ideal spins and springs. Thanks to technological progress, the spin/spring coupling constant greatly exceeds the decoherence rate of the system, so that spins and springs get strongly quantum-entangled. This strong coupling regime is exploited by numerous teams to perform quantum algorithms with a growing number of quantum bits. 1 In this context, dissipation sources, which cause decoherence, appear as the physicist enemy number one, which limits the size of quantum computers and their performances. A lot of efforts is devoted to the development of quantum error correction codes which fight the destruction of quantum information. 2 This requires to increase the number of physical bits used to encode one bit of information, making the realization of complex quantum algorithms even more challenging.