Quantum technology promises revolutionizing applications in information processing, communications, sensing and modelling. However, efficient on-demand cooling of the functional quantum degrees of freedom remains challenging in many solid-state implementations, such as superconducting circuits. Here we demonstrate direct cooling of a superconducting resonator mode using voltage-controllable ele...

The synthesis of Boolean functions, as they are found in many quantum algorithms, is usually conducted in two steps. First, the function is realized in terms of a reversible circuit followed by a mapping into a corresponding quantum realization. During this process, the number of lines and the quantum costs of the resulting circuits have mainly been considered as optimization objectives thus fa...

We present a method for optimizing quantum circuits architecture, based on the notion of a quantum comb, which describes a circuit board where one can insert variable subcircuits. Unexplored quantum processing tasks, such as cloning and storing or retrieving of gates, can be optimized, along with setups for tomography and discrimination or estimation of quantum circuits.

An Investigation into the Realities of a Quantum Datapath by Nemanja Isailovic Doctor of Philosophy in Computer Science University of California, Berkeley Professor John David Kubiatowicz, Chair Quantum computing has shown great potential for being able to solve certain problems which are intractable on classical machines. Peter Shor devised a means to factor large number in polynomial time on ...

An Investigation into the Realities of a Quantum Datapath by Nemanja Isailovic Doctor of Philosophy in Computer Science University of California, Berkeley Professor John David Kubiatowicz, Chair Quantum computing has shown great potential for being able to solve certain problems which are intractable on classical machines. Peter Shor devised a means to factor large number in polynomial time on ...

1. INTRODUCTION In the quantum computational framework there are polynomial time solving algorithms, for problems having exponential classical solutions. The quest is – on one hand – to search if there are other possible effective quantum algorithms and – on the other hand – to be able to produce efficient implementations for the already known algorithms. The most feasible implementation of qua...

Abstract. We exhibit a quantum circuit that performs the Quantum Fourier Transform on n qubits in O(n) depth. Thus, a parallel quantum computer can carry out the QFT in linear time. Griffiths and Niu have already shown this, so this paper is little more than an exercise in quantum circuit design; but perhaps it illustrates a worthwhile idea. We also speculate as to whether the QFT might be in t...

This thesis presents classical emulations of circuit-based and measurement-based quantum com-putation. In order to create emulators faithful to the theory of quantum computation we developthe required mathematics, quantum mechanics and quantum computing background. We justifyour implementations by documenting the theory of each of these subjects in detail and showing ourimpl...

Quantum channels can describe all transformations allowed by quantum mechanics. We adapt two existing works [S. Lloyd and L. Viola, Phys. Rev. A 65, 010101 (2001) and E. Andersson and D. K. L. Oi, ibid. 77, 052104 (2008)] to superconducting circuits, featuring a single qubit ancilla with quantum nondemolition readout and adaptive control. This construction is efficient in both ancilla dimension...

We propose the analog-digital quantum simulation of the quantum Rabi and Dicke models using circuit quantum electrodynamics (QED). We find that all physical regimes, in particular those which are impossible to realize in typical cavity QED setups, can be simulated via unitary decomposition into digital steps. Furthermore, we show the emergence of the Dirac equation dynamics from the quantum Rab...