My Math Forum  

Go Back   My Math Forum > Science Forums > Computer Science

Computer Science Computer Science Forum


Thanks Tree1Thanks
  • 1 Post By weirddave
Reply
 
LinkBack Thread Tools Display Modes
May 31st, 2016, 09:06 PM   #1
Senior Member
 
Joined: May 2015
From: Arlington, VA

Posts: 229
Thanks: 23

Math Focus: Number theory
Efficiency of quantum computing

The World Wide Web contains over 10^21 bytes. At least how many qubits (binary units of quantum information) would be needed to represent it?
Loren is offline  
 
November 28th, 2016, 03:07 AM   #2
Member
 
AshBox's Avatar
 
Joined: Oct 2016
From: labenon

Posts: 33
Thanks: 4

Hi, I have read somewhere this information. I hope this will help you.

"A theorem is proven for quantum information theory that is analogous to the noiseless coding theorem of classical information theory. In the quantum result, the von Neumann entropy S of the density operator describing an ensemble of pure quantum signal states is equal to the number of spin-1/2 systems (‘‘quantum bits’’ or ‘‘qubits’’) necessary to represent the signal faithfully. The theorem holds whether or not the signal states are orthogonal. Related results are also presented about the fidelity of quantum coding and about representing entangled quantum states."
AshBox is offline  
November 28th, 2016, 06:10 AM   #3
Senior Member
 
Joined: Apr 2014
From: UK

Posts: 710
Thanks: 271

At any given time, 0 qubits are required to represent it as the result is all the bytes and is fixed.
If you wanted to represent the changes over time you would need to constrain the changes to a measurable number in order to define the number of qubits needed to uniquely identify the differences.
If you want to represent every possible state of every byte, you'd need 73 qubits
Thanks from Loren
weirddave is offline  
November 29th, 2016, 09:36 PM   #4
Senior Member
 
Joined: May 2015
From: Arlington, VA

Posts: 229
Thanks: 23

Math Focus: Number theory
I get 70 qubits; my math is rustier than my physics, though.

(ln|10|/ln|2|)21~70
Loren is offline  
December 1st, 2016, 08:19 AM   #5
Senior Member
 
Joined: Apr 2014
From: UK

Posts: 710
Thanks: 271

try 8*10^21
weirddave is offline  
Reply

  My Math Forum > Science Forums > Computer Science

Tags
computing, efficiency, quantum



Thread Tools
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Driver Efficiency thomasedillon1520 Number Theory 7 June 10th, 2015 05:49 AM
Efficiency Question thomasedillon1520 Elementary Math 0 June 8th, 2015 08:17 PM
Algorithm efficiency jhuntley Computer Science 7 May 9th, 2014 03:20 PM
The factorial efficiency of Bayes Rule BenFRayfield Advanced Statistics 0 July 31st, 2013 09:33 AM
Engine Efficiency???????????????? how?? imcutenfresa Calculus 1 October 13th, 2009 05:27 PM





Copyright © 2017 My Math Forum. All rights reserved.