His work on quantum algorithms began with a 1985 paper, later expanded in 1992 along with Richard Jozsa to produce the Deutsch–Jozsa algorithm, one of the first examples of a quantum algorithm that is exponentially faster than any possible deterministic classical algorithm. In his 1985 paper, he also suggests the use of entangled states and Bell's theorem for quantum key distribution. In his nomination for election as a Fellow of the Royal Society in 2008, his contributions were described as:
" laid the foundations of the quantum theory of computation, and has subsequently made or participated in many of the most important advances in the field, including the discovery of the first quantum algorithms, the theory ofquantum logic gates and quantum computational networks, the first quantum error-correction scheme, and several fundamental quantum universality results. He has set the agenda for worldwide research efforts in this new, interdisciplinary field, made progress in understanding its philosophical implications and made it comprehensible to the general public, notably in his book The Fabric of Reality."
Since 2012, he has been working on constructor theory, an attempt at generalizing the quantum theory of computation to cover not just computation but all physical processes. Together with Chiara Marletto, he published a paper in December 2014 entitled Constructor theory of information, that conjectures that information can be expressed solely in terms of which transformations of physical systems are possible and which are impossible.
''The Fabric of Reality''
In his 1997 book The Fabric of Reality, Deutsch details his "Theory of Everything". It aims not at the reduction of everything to particle physics, but rather mutual support among multiversal, computational, epistemological, and evolutionary principles. His theory of everything is somewhat emergentist rather than reductive. There are four strands to his theory:
Karl Popper's epistemology, especially its anti-inductivism and requiring a realist interpretation of scientific theories, as well as its emphasis on taking seriously those bold conjectures that resist falsification.
Richard Dawkins' refinement of Darwinian evolutionary theory and the modern evolutionary synthesis, especially the ideas of replicator and meme as they integrate with Popperian problem-solving.
''The Beginning of Infinity''
Deutsch's second book, The Beginning of Infinity: Explanations that Transform the World, was published on 31 March 2011. In this book, Deutsch views the Enlightenment of the 18th century as near the beginning of a potentially unending sequence of purposeful knowledge creation. He examines the nature of memes and how and why creativity evolved in humans.
