Summary: Molecular Scale Heat Engines and Scalable Quantum Computation
Leonard J. Schulman \Lambda Umesh V. Vazirani y
Abstract
We describe a quantum mechanical heat engine. Like its
classical counterpart introduced by Carnot, this engine car­
ries out a reversible process in which an input of energy to
the system results in a separation of cold and hot regions.
The method begins with a reinterpretation in thermody­
namic terms of a simple step introduced by von Neumann
to extract fair coin flips from sequences of biased coin flips.
Some of the experimental set­ups proposed for imple­
mentation of quantum computers, begin with the quantum
bits of the computer initially in a mixed state. Each qubit
is ffl polarized --- in the state j0i with probability 1+ffl
2 , and in
the state j1i with probability 1\Gammaffl
2 , independently (or nearly
so) of all other bits. The heat engine may be used to trans­
form this initial collection of n qubits into a state in which
a near­optimal m = n[ 1+ffl

Source: Abu-Mostafa, Yaser S. - Department of Mechanical Engineering & Computer Science Department, California Institute of Technology

Collections: Computer Technologies and Information Sciences