Sandia National Laboratories has taken a first step toward creating a practical quantum computer, able to handle huge numbers of computations instantaneously. A "donor" atom propelled by an ion beam is inserted very precisely in microseconds into an industry-standard silicon substrate. The donor atom -- in this case, antimony (Sb) --carries one more electron (five) than a silicon atom (four). Because electrons pair up, the odd Sb electron remains free. Instruments monitor the free electron to determine if, under pressure from an electromagnetic field, it faces up or down, a property called "spin."
Although quantum computing is still in its infancy, enough progress is being made for it to look a little more promising than other "revolutionary" technologies, like fusion power or flying cars. IBM, Intel, and Google all either operate or are producing double-digit qubit computers right now, and there are plans for even larger quantum computers in the future. With this amount of inertia, our quantum computing revolution seems almost certain.
The University of New South Wales (UNSW) has announced the demonstration of a compact sensor for accessing information stored in the electrons of individual atoms, touted as a breakthrough that brings a scalable quantum computer in silicon one step closer. UNSW is banking on silicon being the key to building the first quantum computer and the results of the research, conducted within the Professor Michelle Simmons-led Simmons group at the Centre of Excellence for Quantum Computation and Communication Technology (CQC2T), show how this may be achieved. Quantum bits (qubits) made from electrons hosted on single atoms in semiconductors is a promising platform for large-scale quantum computers, the university believes, and creating qubits by precisely positioning and encapsulating individual phosphorus atoms within a silicon chip is the approach Simmons' teams are taking. Read also: Australia's ambitious plan to win the quantum race However, adding in all the connections and gates required for scale up of the phosphorus atom architecture was the challenge the researchers were faced with. "To monitor even one qubit, you have to build multiple connections and gates around individual atoms, where there is not a lot of room," Simmons said.
A scanning tunnelling microscope image showing the electron wave function of a qubit made from a phosphorus atom precisely positioned in silicon. Scientists from the University of New South Wales (UNSW) have announced making two atom quantum bits (qubits) "talk" to each other in silicon, providing the ability to see their exact position in the solid state. The team, led by Director of the Centre of Excellence for Quantum Computation and Communication Technology (CQC2T) -- and recent recipient of the Australian of the Year award -- UNSW Professor Michelle Simmons, created the atom qubits by precisely positioning and encapsulating individual phosphorus atoms within a silicon chip. The information is stored on the quantum spin of a single phosphorus electron, the university said. "In placing our phosphorus atoms in the silicon to make a qubit, we have demonstrated that we can use a scanning probe to directly measure the atom's wave function, which tells us its exact physical location in the chip.
Here we discussed the advantages and limitations of seven key qubit technologies for designing efficient quantum computing systems. The seven qubit types are: Superconducting qubits, Quantum dots qubits, Trapped Ion Qubits, Photonic qubits, Defect-based qubits, Topological Qubits, and Nuclear Magnetic Resonance (NMR) . They are the seven pathways for designing effective quantum computing systems. Each one of them have their own limitations and advantages. We have also discussed the hierarchies of qubit types.