D-Wave Systems Testing 128Qubit Quantum Computing Chip
How much noise (and of what type) is acceptable varies depending on the computational model used. In AQC, superposition and entanglement of the system’s ground state can be equilibrium properties of the system even in the presence of noise, as long as the noise-induced energy level broadening is less than the energy gap between the ground state and the first excited state throughout a computation.”
Rose elaborated: “Many computer scientists and physicists believe that the AQC computing model is inherently noise tolerant. As for the specifics of how we contend with noise in the system, there are many, many things we do to eliminate, reduce and manage noise.”
Scaling More Difficult than Anticipated
D-Wave said it previously demonstrated a 28qubit machine at the SC07 Supercomputing Conference. The computer did not actually make a physical appearance, but performed a remote demonstration, analyzing a 300-image database, cataloging the similarities among photos. The results of that comparison were then displayed on a two-dimensional grid, grouping similar images together (see Superconductor Week Vol 21, No 23).
The company announced at the time a goal of making a 512qubit machine in the second quarter of 2008 and 1024qubits by the end of that year. Rose said the goal was perhaps overly ambitious. Scaling to 512qubits required a completely new chip design from the ground up, and almost every aspect of the processor design went through a complete redesign.
“Right now it’s looking like 128qubits may be what we will achieve by the end of 2009,” said Rose. “However, if the scaling goes well to 128qubits, it will mean scaling to 512qubits should be easier.”
Further External Investment May Be Needed
At the beginning of 2008 D-Wave announced raising $17 million from venture capitalists including International Investment and Underwriting (IIU) of Dublin, Ireland, Draper Fisher Jurvetson (DFJ), GrowthWorks Capital Ltd, BDC Venture Capital, Harris & Harris, bcIMC and Pender Fund, to be used for product development, operations and business development activity (see Superconductor Week Vol 22, No 2).
“Through the end of 2008 D-Wave has raised another $11 million from Goldman Sachs, and our existing investors are still faithfully backing the company,” said Rose. “The company is well funded for the task, but given the current economic situation we are not ruling out further investment from outside before reaching profitability.”