Archive for the ‘Quantum Computer’ Category.
October 4, 2011
Researchers from Rice University have made progress towards quantum computers. They have created a novel way to build a quantum spin hall topological insulator device. This part is a necessary component of a future low error machine that can store and manipulate data in a rapid fashion. Combining superposition with entanglement will allow CPUs to solve select algorithms at a quicker pace than conventional logic gates. They describe their technique in Physical Review Letters. There are several routes to synthesize quantum processors. These include quantum dots and trapped ions, as a few examples. A main issue is making sure the information that the qubits encode is not lost because of uncontrolled interactions with the environment. The different techniques have varying capabilities when it comes to this aspect. Read More »
September 19, 2011
The Center for Nanoscale Science and Technology (CNST) has created a novel kind of nanophotonic cavity. This device improves the precision of collecting light from a quantum dot (QD). The dots are capable of emitting single photons. Powerful quantum computers may one day rely on these miniature components to solve challenging problems. Currently the applications for QDs have been limited due to the amount of light collected by nearby lenses. This figure can be less than one percent. Now they have found that a novel structure can enhance both the absorption and emission of particles. This material consists of a suspended 200 nm-thick GaAs membrane that has embedded dots encircled with a partially etched dielectric grating. The efficiency rises to 10% because of this innovation. Read More »
September 7, 2011
Quantum dots (QDs) are being investigated as one possible component of ultra-fast computers. The electron spins within these structures can serve as qubits. QDs can also be a source of entangled photons. By entangling the qubits, a processor would be able to take advantage of the parallelism inherent to quantum mechanics. Specific software algorithms could show a significant speed up when run on a machine using these fundamental units. The pyramidal dots themselves can be 100 nanometers high with only 200 atoms for each side. Trying to model molecules quantum mechanically is computationally intensive. Ironically, one of the benefits of quantum computers is being able to simulate molecular processes with greater speed and fidelity. A quantum simulator would be an analog device that could model the intricate details of atomic interactions in a way a digital CPU could not. This may lead to more breakthroughs in chemistry and material science. Currently, though, the amount of entangled qubits is low and this number would have to be increased to hundreds before these specialized computers could become viable in this arena. To help scientists reach that point, they have to be able to emulate QD’s on conventional machines. Any shortcut they find to do this is enormously helpful in expediting the analysis and new work has uncovered a superior method of accomplishing this. Read More »
Researchers from Rice University have made progress towards quantum computers. They have created a novel way to build a quantum spin hall topological insulator device. This part is a necessary component of a future low error machine that can store and manipulate data in a rapid fashion. Combining superposition with entanglement will allow CPUs to solve select algorithms at a quicker pace than conventional logic gates. They describe their technique in Physical Review Letters. There are several routes to synthesize quantum processors. These include quantum dots and trapped ions, as a few examples. A main issue is making sure the information that the qubits encode is not lost because of uncontrolled interactions with the environment. The different techniques have varying capabilities when it comes to this aspect. Read More »
