Results 1 
7 of
7
FewQubit Magnetic Resonance Quantum Information Processors: Simulating Chemistry and Physics
, 2014
"... 1.2 Quantum Algorithms for Chemistry............... 4 ..."
Abstract

Cited by 1 (0 self)
 Add to MetaCart
(Show Context)
1.2 Quantum Algorithms for Chemistry............... 4
c ○ Rinton Press HIGHFIDELITY QUANTUM CONTROL USING ION CRYSTALS IN A PENNING TRAP
, 2009
"... We provide an introduction to the use of ion crystals in a Penning trap [1, 2, 3, 4] for experiments in quantum information. Macroscopic Penning traps allow for the containment of a few to a few million atomic ions whose internal states may be used in quantum information experiments. Ions are laser ..."
Abstract
 Add to MetaCart
(Show Context)
We provide an introduction to the use of ion crystals in a Penning trap [1, 2, 3, 4] for experiments in quantum information. Macroscopic Penning traps allow for the containment of a few to a few million atomic ions whose internal states may be used in quantum information experiments. Ions are laser Doppler cooled [1], and the mutual Coulomb repulsion of the ions leads to the formation of crystalline arrays [5, 6, 7, 8]. The structure and dimensionality of the resulting ion crystals may be tuned using a combination of control laser beams and external potentials [9, 10]. We discuss the use of twodimensional 9Be + ion crystals for experimental tests of quantum control techniques. Our primary qubit is the 124 GHz groundstate electron spin flip transition, which we drive using microwaves [11, 12]. An ion crystal represents a spatial ensemble of qubits, but the effects of inhomogeneities across a typical crystal are small, and as such we treat the ensemble as a single effective spin. We are able to initialize the qubits in a simple state and perform a projective measurement [1] on the system. We demonstrate full control of the qubit Bloch vector, performing arbitrary highfidelity rotations (τπ ∼200 µs). Randomized Benchmarking [13] demonstrates an error per gate (a Paulirandomized π/2 and π pulse pair) of 8±1×10−4. Ramsey interferometry and spinlocking [14] measurements are used to elucidate the limits of qubit coherence in the system, yielding a typical freeinduction decay coherence time of T2 ∼2 ms, and a limiting T1ρ ∼688 ms. These experimental specifications make ion crystals in a Penning trap ideal candidates for novel experiments in quantum control. As such, we briefly describe recent efforts aimed at studying the errorsuppressing capabilities of dynamical
Error characterization and quantum control benchmarking in liquid state NMR using quantum information processing techniques
, 2008
"... ..."
Accelerated Randomized Benchmarking
, 2014
"... Producing useful quantum information devices requires efficiently assessing control of quantum systems, so that we can determine whether we have implemented a desired gate, and refine accordingly. Randomized benchmarking uses symmetry to reduce the difficulty of this task. We bound the resources re ..."
Abstract
 Add to MetaCart
(Show Context)
Producing useful quantum information devices requires efficiently assessing control of quantum systems, so that we can determine whether we have implemented a desired gate, and refine accordingly. Randomized benchmarking uses symmetry to reduce the difficulty of this task. We bound the resources required for benchmarking and show that with prior information, orders of magnitude in accuracy can be obtained. We reach these accuracies with nearoptimal resources, improving dramatically on curve fitting. Finally, we show that our approach is useful for physical devices by comparing to simulations. In developing quantum devices, and in particular devices that implement quantum information processing, an important experimental challenge is to efficiently characterize the quality of control that is affected on a quantum system. By characterizing the quality of a control sequence used to implement an operation, we can apply this knowledge to reason about the utility of that operation for quantum information processing tasks. For
On Experimental Deterministic Quantum Computation with One Quantum Bit (DQC1)
"... I hereby declare that I am the sole author of this thesis. This is a true copy of the thesis, including any required final revisions, as accepted by my examiners. I understand that my thesis may be made electronically available to the public. G. Passante ii Quantum information processors have the ab ..."
Abstract
 Add to MetaCart
(Show Context)
I hereby declare that I am the sole author of this thesis. This is a true copy of the thesis, including any required final revisions, as accepted by my examiners. I understand that my thesis may be made electronically available to the public. G. Passante ii Quantum information processors have the ability to drastically change our world. By manipulating bits of information ruled by the laws of quantum mechanics, computational devices can perform some computations that are classically intractable. Most quantum algorithms rely on pure qubits as inputs and require entanglement throughout the computation. In this thesis, we explore a model of computation that uses mixed qubits without entanglement known as DQC1 (deterministic quantum computation with one quantum bit), using the physical system of liquidstate Nuclear Magnetic Resonance (NMR). Throughout our research, we experimentally implement an algorithm that completely encapsulates the DQC1 model, and take a close look at the quantum nature of DQC1states as given by the
unknown title
, 2009
"... Scalable approaches to the characterization of open quantum system dynamics by ..."
Abstract
 Add to MetaCart
(Show Context)
Scalable approaches to the characterization of open quantum system dynamics by