IBM Doubling ‘Quantum Volume’ Annually. 
But only since 2017.  Yet, Big Blue, has released data showing the comparative improvement of newer IBM quantum computing systems while developing the metric of Quantum Volume.

According to IBM, the performance of a particular quantum computer can be characterized on two levels: metrics associated with the system’s qubits in the quantum chip and overall system performance.  

As simple as these metrics appear, the IBM Q Network quantum computers, Tenerife (IBM Q Experience), Tokyo (IBM Q Network), Poughkeepsie (IBM Q Network), and IBM Q System One, (soon to join the IBM Q Network), show decreasing qubit error rates and increasing system performance across each iteration of the “Q” systems.  

But is this simple measure accurate?   Not accurate enough to judge a quantum computing system’s performance.  To move beyond simple metrics, IBM conceived Quantum Volume, “a full-system performance metric that accounts for gate and measurement errors as well as device cross talk and connectivity, and circuit software compiler efficiency.”

“To achieve Quantum Advantage in the 2020s, we [IBM] need to at least double Quantum Volume every year.”

Defining Quantum Volume.  From the corresponding study developing the metric: “The quantum volume is linked to system error rates, and is empirically reduced by uncontrolled interactions within the system.  It quantifies the largest random circuit of equal width and depth that the computer successfully implements.  Quantum computing systems with high-fidelity operations, high connectivity, large calibrated gate sets, and circuit rewriting toolchains are expected to have higher quantum volumes.  The quantum volume is a pragmatic way to measure and compare progress toward improved system-wide gate error rates for near-term quantum computation and error-correction experiments.”

For IBM, the current period of quantum computing, the Noisy Intermediate-Scale Quantum (NISQ) era of quantum computing, “is an exciting time on all fronts — from hardware, to software, to physics, to benchmarking.”

Big Blue foresees much work to accomplish for improving Quantum Volume on its quantum computing systems.  The company plans to make quantum computing systems with higher performance, yet.  And higher-performance quantum computing may be here sooner than one may think – “In the second half of 2019, upon opening our [IBM’s] new quantum computation center in Poughkeepsie, NY.”

Results and tweaking of Quantum Volume are being presented this week at the 2019 American Physical Society March Meeting, March 4 – 8, in Boston, MA.

Reference is found at IBM…

Study defining Quantum Volume protocol [PDF] found here…