22 research outputs found
Optimal control, geometry, and quantum computing
We prove upper and lower bounds relating the quantum gate complexity of a
unitary operation, U, to the optimal control cost associated to the synthesis
of U. These bounds apply for any optimal control problem, and can be used to
show that the quantum gate complexity is essentially equivalent to the optimal
control cost for a wide range of problems, including time-optimal control and
finding minimal distances on certain Riemannian, subriemannian, and Finslerian
manifolds. These results generalize the results of Nielsen, Dowling, Gu, and
Doherty, Science 311, 1133-1135 (2006), which showed that the gate complexity
can be related to distances on a Riemannian manifoldComment: 7 Pages Added Full Names to Author
Empirical Determination of Bang-Bang Operations
Strong and fast "bang-bang" (BB) pulses have been recently proposed as a
means for reducing decoherence in a quantum system. So far theoretical analysis
of the BB technique relied on model Hamiltonians. Here we introduce a method
for empirically determining the set of required BB pulses, that relies on
quantum process tomography. In this manner an experimenter may tailor his or
her BB pulses to the quantum system at hand, without having to assume a model
Hamiltonian.Comment: 14 pages, 2 eps figures, ReVTeX4 two-colum
Diverse perspectives on interdisciplinarity from the Members of the College of the Royal Society of Canada
Various multiple-disciplinary terms and concepts (although most commonly “interdisciplinarity”,
which is used herein) are used to frame education, scholarship, research, and interactions within
and outside academia. In principle, the premise of interdisciplinarity may appear to have many
strengths; yet, the extent to which interdisciplinarity is embraced by the current generation of academics, the benefits and risks for doing so, and the barriers and facilitators to achieving interdisciplinarity represent inherent challenges. Much has been written on the topic of interdisciplinarity, but to
our knowledge there have been few attempts to consider and present diverse perspectives from scholars, artists, and scientists in a cohesive manner. As a team of 57 members from the Canadian College
of New Scholars, Artists, and Scientists of the Royal Society of Canada (the College) who self-identify as being engaged or interested in interdisciplinarity, we provide diverse intellectual, cultural, and
social perspectives. The goal of this paper is to share our collective wisdom on this topic with the
broader community and to stimulate discourse and debate on the merits and challenges associated
with interdisciplinarity. Perhaps the clearest message emerging from this exercise is that working
across established boundaries of scholarly communities is rewarding, necessary, and is more likely
to result in impact. However, there are barriers that limit the ease with which this can occur (e.g., lack
of institutional structures and funding to facilitate cross-disciplinary exploration). Occasionally, there
can be significant risk associated with doing interdisciplinary work (e.g., lack of adequate measurement or recognition of work by disciplinary peers). Solving many of the world’s complex and pressing
problems (e.g., climate change, sustainable agriculture, the burden of chronic disease, and aging populations) demand thinking and working across long-standing, but in some ways restrictive, academic
boundaries. Academic institutions and key support structures, especially funding bodies, will play an
important role in helping to realize what is readily apparent to all who contributed to this paper—that
interdisciplinarity is essential for solving complex problems; it is the new norm. Failure to empower
and encourage those doing this research will serve as a great impediment to training, knowledge,
and addressing societal issues