Quantum Computers

In a step toward a generation of ultrafast computers, physicists have used bursts of radio waves to briefly create 10 billion quantum-entangled pairs of subatomic particles in silicon. The research offers a glimpse of a future computing world in which individual atomic nuclei store and retrieve data and single electrons shuttle it back and forth.

This is one of a range of competing approaches to making qubits, the quantum computing equivalent of today's transistors. Transistors store information on the basis of whether they are on or off. In the experiment, qubits store information in the form of the spin of an atomic nucleus or an electron. The storage ability is dependent on entanglement, in which a change in one particle instantaneously affects other particles even if they are widely separated. The new approach has significant potential, scientists said, because it might permit quantum computer designers to exploit low-cost and easily manufactured components and technologies now widely used in the consumer electronics industry.

Unlike today's binary computers, in which transistors can be in either an "on" or an "off" state, quantum computing exploits the notion of superposition, in which a qubit can be constructed to represent both a 1 and a zero state simultaneously.

The potential power of quantum computing comes from the possibility of performing a mathematical operation on both states simultaneously. In a two-qubit system it would be possible to compute on four values at once, in a three-qubit system on eight at once, in a four-qubit system on 16, and so on. As the number of qubits increases, potential processing power increases exponentially.

There is, of course, a catch. The mere act of measuring or observing a qubit can strip it of its computing potential. So researchers have used quantum entanglement — in which particles are linked, so that measuring a property of one instantly reveals information about the other, no matter how far apart the two particles are—to extract information. But, creating and maintaining qubits in entangled states has been tremendously challenging.

The new approach is based on a highly purified silicon isotope that is doped with phosphorus atoms. One of the principal advantages of the new silicon-based approach is that the group believes that it will be able to maintain the entangled state needed to preserve quantum information as long as several seconds, far longer than competing technologies which currently measure the persistence of entanglement for billionths of a second.

The advance indicates that there is an impending convergence between the subatomic world of quantum computers and today's classical microelectronic systems, which are reaching a level of miniaturization in which wires and devices are composed of just dozens or hundreds of atoms.

BookCart learning activities are a one-stop solution for teachers and students in conducting 21st Century inquiry-based learning activities. Great editor-selected resources + essential questions for critical thinking + student directions ensure that no time is wasted and students have everything they need to maximize learning.

The learning activity for this month is just one of hundreds of BookCarts that teachers and librarians can copy into their local collection and use right away. Here's how to do it:

• Logon to the eLibrary Science TEACHER EDITION.
• Click the BOOKCART ADMIN tab at the top of the Teacher Edition.
• Click the PROQUEST CARTS tab.
• Type "Quantum Computing with Qubits" in the SEARCH box.
• Click the COPY icon (middle one) in the ACTIONS column to the right of this title.
• Click RETURN TO MY LOCAL CARTS.

Librarians or teachers can edit this BookCart to customize it for their students:

• Click the new BookCart TITLE with the prefix "COPY OF".
• Delete "Copy of" and then type your name in the AUTHOR boxes and your initials in the EMAIL box (required info).
• Option: Edit any ESSENTIAL QUESTIONS for your students in the DESCRIPTION box.
• Option: Edit the existing STUDENT DIRECTIONS in the Description box.
• Scroll down and click SAVE.
• Click RETURN TO MY LOCAL CARTS.

Assign students to write a report of at least 150 words or a presentation of at least seven slides. Student should cite at least three resources and address the following essential questions for critical thinking (you can add or substitute others):

• What properties of matter make quantum computing possible?
  
  
• What are the advantages of quantum computers?
  
  
• What problems must be solved in order to use quantum computing effectively?
  
  
• What practical large-scale applications would quantum computing provide?

Type "Quantum Computers and Qubits" in the Search box > Enter "Quantum OR Qubits" in the Document Title box

Your students can use our custom ProQuest models for written and PowerPoint-style reports.

Teachers may be interested in a ProQuest flexible rubrics model for evaluating inquiry-based learning activities.

Educators may also wish to employ the Quizinator Web tool (free, but registration required) for creating a variety of printed resources, including short assessments.