Energy-Efficient Quantum Computing

In the near future, a major challenge in quantum computing is to scale up robust qubit prototypes to practical problem sizes and to implement comprehensive error correction for computational precision. Due to inevitable quantum uncertainties in resonant control pulses, increasing the precision of quantum gates comes with the expense of increased energy consumption. Consequently, the power dissipated in the vicinity of the processor in a well-working large-scale quantum computer seems unacceptably large in typical systems requiring low operation temperatures. Here, we introduce a method for qubit driving and show that it serves to decrease the single-qubit gate error without increasing the average power dissipated per gate. Previously, single-qubit gate error induced by a bosonic drive mode has been considered to be inversely proportional to the energy of the control pulse, but we circumvent this bound by reusing and correcting itinerant control pulses. Thus our work suggests that heat dissipation does not pose a fundamental limitation, but a necessary practical challenge in future implementations of large-scale quantum computers.