Information is physical -- it is stored and processed in
physical systems. So, the laws of information processing -- e.g.,
what is possible -- are derived from the physics of the underlying
bits. Bits that obey quantum physics (a.k.a. "qubits") enable a whole
new set of protocols and algorithms, collectively known as quantum
information science. After ~30 years of effort, we have: (1) a
variety of applications for quantum computers; and (2) several
promising experimental technologies for building quantum computers.
Unfortunately, most of the applications require thousands of qubits…
and quantum devices of this size are probably 10-20 years away.
Fortunately, there ARE interesting and useful applications for quantum
information processors comprising 100, 10, or even just 2 qubits!
Such devices aren't useful for computation -- they can be simulated
effectively on classical computers -- but they can process existing
quantum information with remarkable efficiency. I'll present two such
examples. First, quantum devices as small as 1 qubit can be used to
enhance the detection of small forces, by discriminating with optimal
accuracy between distinct quantum states. Second, somewhat larger
quantum devices can be used to compress quantum data, and to
concentrate quantum entanglement -- which can then be used as a
resource to enable large-scale quantum computing.
Refreshments will be served half an hour before the start of the colloquium in Weniger 305.