to develop quantum-logic
components and quantum
information systems based on
trapped ions, in support of
new atomic frequency standards
and a national program
aimed at advancing computation
and communication.
INTENDED OUTCOME AND
BACKGROUND
We conduct research on the development
and properties of prototype quantum-
logic devices consisting of small
numbers of electromagnetically trapped
and laser-cooled ions serving as quantum
bits (qubits). This research comprises
quantum computing, quantum
measurement (including noise reduction
in frequency standards), and development
of new classes of quantum-logicbased
frequency standards.
This project arose as part of a long-term
research program on ion-based frequency
standards. In particular, the goal of
reducing fundamental quantum projection
noise suggested the possibility of
using similar approaches for quantum
computing and quantum metrology.
Division researchers soon became leaders
in quantum computing research, and
NIST-wide programs in quantum computing
and quantum communications
rapidly developed and demonstrated
significant success.
Our focus on quantum computing
meets two primary needs. First, quantum
computing research is a national
priority to ensure economic and physical
security, with substantial investment
by both defense and civilian funding
agencies. Our unique expertise in quantum
state engineering has made the
trapped-ion quantum computing program
a world-leading effort.
Second, Division work on quantum state engineering serves our time and frequency metrology mission. The “logic clock” optical
frequency standard described earlier is an excellent example of quantum information
processing techniques being applied to develop a new type of atomic clock, which is already performing comparably to the world’s best optical frequency standards. It can, in principle, be adapted to other species that hold potential for even better performance. The Division has also demonstrated
Heisenberg-limited spectroscopy with three entangled ions, in a scheme that could be scaled to an arbitrary number of ions or atoms. In principle, this could dramatically reduce the averaging time required
for a frequency standard to reach its statistical uncertainty limit, substantially improving the performance, and broadening
the applications, of atomic clocks.
Accomplishments
Progress in Quantum State Manipulation for Quantum Computing and Quantum Measurement
Figure 8. David Wineland adjusting one of the systems used for studying quantum-logic gates, and a new planar electrode ion trap for scalable quantum computing research. |
The Division’s quantum computing and quantum measurement program continues to make strong progress. We have now demonstrated all the so-called DiVincenzo criteria for a practical, scalable quantum computer, although of course much additional research and development is required before a practical quantum computer
is realized.
In the past several years, Division scientists
have demonstrated for the first time deterministic teleportation of quantum information on atomic (ionic) qubits— paving the way for efficient transfer of information
in a complex quantum computer—
and robust quantum error correction schemes necessary for practical, scalable quantum computers. Division scientists achieved a world record of entangling six beryllium ions in a Schrödinger cat state— general considered the most useful and most highly entangled state for quantum information processing.
More recently, the Division has demonstrated
semi-classical quantum Fourier transform operations on an array of three trapped beryllium ions. Performing Fourier transform operations is a key step towards realizing Shor’s algorithm in a scalable quantum computer, a method to quickly factor large integers for quantum cryptography.
The Division has demonstrated world-leading coherence times of greater than 10 seconds for single physical qubit states, orders of magnitude greater than previous
experiments, and orders of magnitude greater than the typical microsecond-order operation times. In principle this enables many thousands of operations to be performed without loss of coherence. And the Division demonstrated the first successful experimental purification of two-ion entangled states, overcoming the effects of decoherence when one qubit in an entangled pair is physically transported to another location.
A major challenge for developing a large-scale quantum computer based on trapped ions is to develop an architecture that can simultaneously handle a large number of ion qubits, including laser cooling, quantum processing operations, storage and transport of qubits throughout the computer, and other operations. Recently, the Division has demonstrated a planar geometry for ion traps, where the previous three-dimensional array of electrodes has been “unfolded” into a planar array that still generates an electromagnetic potential well to trap and move the ion qubits.
This new planar geometry is highly promising for a practical, scalable solution.
First strategic focus |
Second strategic focus |
Third strategic focus |
Fourth strategic focus
"Technical Activities 2005-2007" - Table of Contents |
