It’s high “NOON” for microwave photons
SANTA BARBARA, Calif. – An important milestone toward the realization
of a large-scale quantum computer and further demonstration of a new level of the
quantum control of light were accomplished by a team of scientists at the University
of California, Santa Barbara (UCSB), Zhejiang University of China and NEC Corp.
The researchers describe how they used a superconducting quantum
integrated circuit to generate unique quantum states of light known as “NOON”
states. Generated from microwave-frequency photons, the states were created and
stored in two physically separated microwave storage cavities. They explain that
quantum NOON states were created using one, two or three photons; all photons were
located in one cavity, leaving the other cavity empty.
This chip contains the superconducting integrated circuit used to
generate NOON microwave states. Courtesy of Erik Lucero, UCSB.
In this configuration, which is made possible by quantum mechanics,
findings indicate that there is a 50 percent chance of seeing all the photons in
one cavity and a 50 percent chance of not finding any. However, probing the cavity
gently before looking inside it changes the quantum state, and the effect of probing
can be detected even if the cavity is determined later to be empty. These findings
were published in Physical Review Letters, Feb. 7, 2011 (doi: 10.1103/ PhysRevLett.106.060401).
“It’s kind of like the states are ghostly twins or
triplets,” said Haohua Wang, a postdoctoral fellow in physics at UCSB. “They
are always together, but somehow you never know where they are. They also have a
mysterious way of communicating, so they always seem to know what is going to happen.”
The quantum integrated circuit, which includes superconducting
quantum bits along with the microwave storage cavities, could eventually become
part of a quantum computational architecture, the scientists concluded.
- quantum mechanics
- The science of all complex elements of atomic and molecular spectra, and the interaction of radiation and matter.
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