Abstract:
We will review IBM’s current approach towards building a quantum computer
using superconducting qubits. Large systems will require quantum error
correction techniques and recently it has been show that such techniques
based on two-dimensional surface codes have a remarkably low fault tolerant
threshold. Surface codes have guided our vision for several years and form
the core of our approach. We will show experimental progress towards
implementing surface codes, including a description of our qubits whose
coherence times (T1, T2) are near 50 micro-seconds. Together with
100ns-400ns long all-microwave two-qubit gates, we show two-qubit gate
fidelities near or even above 95%. Because our approach does not require
explicit frequency tuning of the qubits, calibration routines are straight
forward. We will conclude by outlining some future challenges that face the
community on our quest towards larger systems, as well as pointing out
fruitful areas of quantum engineering which have influenced other branches
of physics.