Startseite
Podcasts
From First Principles Podcast
How Quantum Computing Actually Works (Part 1) (EP 54)

How Quantum Computing Actually Works (Part 1) (EP 54)

From First Principles vor 2 Monaten

0:00

2:11:11

Quantum computers do not simply “try every answer at once.” So what
do they actually do—and why have governments and technology
companies spent billions trying to build them? In Part 1 of our
two-part quantum computing deep dive, Lester Nare and Krishna
Choudhary build the field from first principles. The series was
prompted by a new Nature cover paper, A digitally controlled
silicon quantum processing unit, co-authored by Krishna and members
of the HRL Quantum Team and collaborators. Before getting into that
hardware in Part 2, we first need to understand why anyone wanted
to build a quantum computer in the first place. We begin with
Bell’s theorem and the failure of local hidden-variable
explanations of quantum mechanics. From there, we follow the
realization that information is fundamentally physical through Rolf
Landauer, reversible computation, Charles Bennett, Tommaso Toffoli,
Paul Benioff, and the origins of quantum information science. Then
Richard Feynman changes the question. Straightforward classical
simulation of an interacting quantum system requires tracking a
state space that grows exponentially with the number of particles.
If nature itself is quantum mechanical, Feynman asks, why not build
a computer that is quantum mechanical too? David Deutsch formalizes
the universal quantum computer and introduces the first quantum
algorithm. Using the Deutsch–Jozsa problem, the double-slit
experiment, and Feynman’s path-integral intuition, we explain what
a quantum algorithm is actually exploiting: carefully engineered
constructive and destructive interference. Finally, we reach the
discoveries that turned quantum computing from an academic
curiosity into a strategic technology. Daniel Simon develops an
early exponential quantum speedup. Peter Shor recognizes how the
underlying mathematics can be used to attack problems central to
public-key cryptography. Lov Grover follows with a quantum search
algorithm—and suddenly governments have a very different reason to
care about quantum machines. We also explore quantum money, quantum
cryptography, the many-worlds interpretation, Google Willow and
parallel-universe headlines, post-quantum security, and what useful
quantum computers may ultimately be good for. Part 2: How do you
actually build one? Nature paper:A digitally controlled silicon
quantum processing unitDOI: 10.1038/s41586-026-10754-7 Link:
https://www.nature.com/articles/s41586-026-10754-7 Explore the FFP
science funding tracker:ffppod.com/funding Support the
show:ffppod.com.com/donate Follow:@FFPPod on X / Instagram / TikTok
/ Facebook