Quantum Computers Move A QuBit Closer To Reality
By John Blyler
The first “dimmer” switch to link a quantum bit (qubit) of information and a quantum bus has been developed by scientists at the National Institute of Standards and Technology (NIST). This switch can flexibly tune interactions between quantum storage and transporting technologies, effectively moving the creation of a quantum computer one step closer to reality.
What would a quantum computer mean to today’s hardware and software developers? It may not require a “quantum leap” to find out.
In the early days of computers, hardware was king. Software was written well after the hardware platform was built. Today, system designers have to balance the simultaneous co-design and co-verification of both hardware and software systems. In the near future, as hardware becomes more and more of a commodity, the software may eclipse hardware in the product life cycle to become the primary system driver (see ‘Good’ Vs. ‘Good Enough’).
What does the future hold? Certainly traditional electronic-based computers will be around for a long, long time. But hardware—at the lowest process nodes—is reaching manufacturability limits. Further, the software the runs on computers may also have inherent limitations.
Back in the 1930s, Alan Turing proved there was a class of problems that could never be solved by a computer. There are other problems that, while theoretically solvable, would take the fastest computer the entire lifetime of the universe to reach an answer – even if the answer is only “42.”
Parallel processing has extended the reach of problems that computers can solve. But to be truly effect, software must be written explicitly for a parallel processing architecture—not a collection of general-purpose processors in a multicore arrangement. Further, the operating system must be equally specialized to split the processing tasks. To date, parallel process technology has been used to speed up the computation of repetitive tasks, not to handle truly immense computing challenges.
This is where quantum computing may help. Back in 1981, the Nobel-prize winning physicist Richard Feynman suggested that a quantum computer could be used to absolutely—not approximately—model the physical world. Since, at the most basic of levels, the world runs on quantum principles, it makes sense that a computer used to really model the world must also operate at a quantum level in order to perfectly simulate quantum effects.
And so the challenge began to create a quantum computer that could replace our Boolean-based world of ones and zeros with the quantum state of a particle as a bit. Thanks to the strangeness of quantum mechanics, this bit – called a “qubit” – can simulatenously be in more than one state at once. Sounds crazy? Just ask Schrodinger’s cat for help, but be sure to pick the live one.
It’s this qubit that is at the heart of the recent NIST announcement. The Quantum Information Program group in Boulder, Colo., developed a “dimmer” switch for supercomputing circuits that connects a qubit and a quantum bus. The “bus” is really a resonant cavity that serves as a channel for moving information (qubits) from one section of the computer to another. The new NIST switch “can reliably tune the interaction strength or rate between the two types of circuits—a qubit and a bus—from 100MHz to nearly zero.” In essence, the switch enables control of the interactions between many of the circuit elements that will be needed to build a quantum computer.
Quantum computers still don’t exist, but the basic building blocks are being researched and prototyped. Would such computers replace their electronic brethren? Not in our lifetime. Still, the development of these future computers may well affect the way we view hardware and software today.
Colorized micrograph of superconducting circuit used in NIST quantum computing research.
Tags: quantum computing, qubits