Stephen S. Bullock

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The pressure of fundamental limits on classical computation and the promise of exponential speedups from quantum effects have recently brought quantum circuits to the attention of the EDA community [10, 17, 4, 16, 9]. We discuss efficient circuits to initialize quantum registers and implement generic quantum computations. Our techniques yield circuits that(More)
A unitary operator U = ∑ j,k u j,k|k〉〈 j| is called diagonal when u j,k = 0 unless j = k. The definition extends to quantum computations, where j and k vary over the 2n binary expressions for integers 0,1 · · · ,2n−1, given n qubits. Such operators do not affect outcomes of the projective measurement {〈 j| ; 0 ≤ j ≤ 2n − 1} but rather create arbitrary(More)
The two-qubit canonical decomposition SU(4) = [SU(2)⊗ SU(2)]∆[SU(2)⊗ SU(2)] writes any two-qubit quantum computation as a composition of a local unitary, a relative phasing of Bell states, and a second local unitary. Using Lie theory, we generalize this to an n-qubit decomposition, the concurrence canonical decomposition (C.C.D.) SU(2n) = KAK. The group K(More)
We show how to implement an arbitrary two-qubit unitary operation using any of several quantum gate libraries with small a priori upper bounds on gate counts. In analogy to library-less logic synthesis, we consider circuits and gates in terms of the underlying model of quantum computation, and do not assume any particular technology. As increasing the(More)
Operators acting on a collection of two-level quantum-mechanical systems can be represented by quantum circuits. This work presents a new universal quantum circuit capable of implementing any unitary operator. The circuit has a top-down structure, and the parameters for individual unitaries can be computed using standard matrix analysis algorithms. The(More)
On pure states of n quantum bits, the concurrence entanglement monotone returns the norm of the inner product of a pure state with its spin-flip. The monotone vanishes for n odd, but for n even there is an explicit formula for its value on mixed states, i.e., a closed-form expression computes the minimum over all ensemble decompositions of a given density.(More)
BACKGROUND Tumescent liposuction is a new method of liposuction under local anesthesia that has been developed by dermatologic surgeons. OBJECTIVE To determine the safety of tumescent liposuction in a large group of patients treated by dermatologic surgeons. METHODS A survey questionnaire was sent to 1,778 Fellows of the American Society for(More)