Browse Definitions:
Definition

quantum computer

A quantum computer is a machine, as-yet hypothetical, that performs calculations based on the behavior of particles at the sub-atomic level. Such a computer will be, if it is ever developed, capable of executing far more millions of instructions per second (MIPS) than any previous computer. Such an exponential advance in processing capability would be due to the fact that the data units in a quantum computer, unlike those in a binary computer, can exist in more than one state at a time. In a sense, the machine "thinks" several "thoughts" simultaneously, each "thought" being independent of the others even though they all arise from the same set of particles.

Engineers have coined the term qubit (pronounced KYEW-bit) to denote the fundamental data unit in a quantum computer. A qubit is essentially a bit (binary digit) that can take on several, or many, values simultaneously. The theory behind this is as bizarre as the theory of quantum mechanics, in which individual particles appear to exist in multiple locations. One way to think of how a qubit can exist in multiple states is to imagine it as having two or more aspects or dimensions, each of which can be high (logic 1) or low (logic 0). Thus if a qubit has two aspects, it can have four simultaneous, independent states (00, 01, 10, and 11); if it has three aspects, there are eight possible states, binary 000 through 111, and so on.

Quantum computers might prove especially useful in the following applications:

  • Breaking ciphers
  • Statistical analysis
  • Factoring large numbers
  • Solving problems in theoretical physics
  • Solving optimization problems in many variables

The main difficulty that the research-and-development engineers have encountered is the fact that it is extremely difficult to get particles to behave in the proper way for a significant length of time. The slightest disturbance will cause the machine to cease working in quantum fashion and revert to "single-thought" mode like a conventional computer. Stray electromagnetic fields, physical movement, or a tiny electrical discharge can disrupt the process.

This was last updated in June 2010

Continue Reading About quantum computer

Start the conversation

Send me notifications when other members comment.

By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy

Please create a username to comment.

-ADS BY GOOGLE

Extensiones de Documento y Formatos de Documento

Accionado por:

SearchCompliance

  • smart contract

    A smart contract, also known as a cryptocontract, is a computer program that directly controls the transfer of digital currencies...

  • risk map (risk heat map)

    A risk map, also known as a risk heat map, is a data visualization tool for communicating specific risks an organization faces. A...

  • internal audit (IA)

    An internal audit (IA) is an organizational initiative to monitor and analyze its own business operations in order to determine ...

SearchSecurity

  • evil maid attack

    An evil maid attack is a security exploit that targets a computing device that has been shut down and left unattended.  An evil ...

  • Common Body of Knowledge (CBK)

    In security, Common Body of Knowledge (CBK) is a comprehensive framework of all the relevant subjects a security professional ...

  • rootkit

    A rootkit is a program or, more often, a collection of software tools that gives a threat actor remote access to and control over...

SearchHealthIT

  • value-based healthcare

    Value-based healthcare, also known as value-based care, is a payment model that rewards healthcare providers for providing ...

  • health informatics

    Health informatics is the practice of acquiring, studying and managing health data and applying medical concepts in conjunction ...

  • clinical trial

    A clinical trial, also known as a clinical research study, is a protocol to evaluate the effects and efficacy of experimental ...

SearchDisasterRecovery

  • crisis communication

    Crisis communication is a method of corresponding with people and organizations during a disruptive event to provide them with ...

  • Zerto

    Zerto is a storage software vendor that specializes in enterprise-class business continuity and disaster recovery in virtual and ...

  • crisis management plan (CMP)

    A crisis management plan (CMP) is a document that outlines the processes an organization will use to respond to a critical ...

SearchStorage

  • SSD write cycle

    An SSD write cycle is the process of programming data to a NAND flash memory chip in a solid-state storage device.

  • data storage

    Data storage is the collective methods and technologies that capture and retain digital information on electromagnetic, optical ...

  • hard disk

    A hard disk is part of a unit -- often called a disk drive, hard drive or hard disk drive -- that stores and provides relatively ...

SearchSolidStateStorage

  • hybrid hard disk drive (HDD)

    A hybrid hard disk drive is an electromechanical spinning hard disk that contains some amount of NAND Flash memory.

Close