The effect of anatase, rutile, and amorphous TiO 2 nanoparticles on the combustion of solid rocket propellant was investigated. Each additive increased the burning rate of propellant strands by 30%. Typical fast-burning propellants are unstable due to oversensitivity to pressure variations, but the anatase additive yielded propellants with high yet stable burning rates over a broad pressure range. Anatase nanoparticles also catalyzed the high-temperature decomposition of ammonium perchlorate, a key component of solid propellant.

PyGSTi is a Python software package for assessing and characterizing the performance of quantum computing processors. It can be used as a standalone application, or as a library, to perform a wide variety of quantum characterization, verification, and validation (QCVV) protocols on as-built quantum processors. We outline pyGSTi’s structure, and what it can do, using multiple examples. We cover its main characterization protocols with end-to-end implementations. These include gate set tomography, randomized benchmarking on one or many qubits, and several specialized techniques. We also discuss and demonstrate how power users can customize pyGSTi and leverage its components to create specialized QCVV protocols and solve user-specific problems.

In order to achieve the high-fidelity quantum control needed for a broad range of quantum information technologies, reducing the effects of noise and system inhomogeneities is an essential task. It is well known that a system can be decoupled from noise or made insensitive to inhomogeneous dephasing dynamically by using carefully designed pulse sequences based on square or delta-function waveforms such as Hahn spin echo or CPMG. However, such ideal pulses are often challenging to implement experimentally with high fidelity. Here, we uncover a new geometrical framework for visualizing all possible driving fields, which enables one to generate an unlimited number of smooth, experimentally feasible pulses that perform dynamical decoupling or dynamically corrected gates to arbitrarily high order. We demonstrate that this scheme can significantly enhance the fidelity of singlequbit operations in the presence of noise and when realistic limitations on pulse rise times and amplitudes are taken into account.In recent years, the prospect of enhanced technologies that exploit the principles of quantum mechanics has attracted great interest from many fields in physics and beyond. These efforts are geared toward several envisioned applications, including information processing [1-6], secure communications [7,8], and sensing [9][10][11], and enormous progress has been made in engineering and optimizing coherent quantum systems for these purposes. However, decoherence caused by the environment or other factors remains a primary impediment to realizing quantum technologies [12][13][14][15]; overcoming this challenge requires improvements not only in system engineering [16][17][18], but also in how such systems are controlled.It has been known since the early days of nuclear magnetic resonance that it is possible to design driving fields that suppress adverse effects caused by fluctuations in the system Hamiltonian or in the driving field itself. The simplest example is the Hahn spin echo [19], in which a fast (δ-function) π-pulse is applied halfway through the evolution of a precessing spin, guaranteeing that the spin returns to its initial state at the end of the evolution regardless of the precession rate. This has long been a standard technique to combat inhomogeneous dephasing -the loss of coherence due to variations in precession frequency in spin ensembles. Spin echo and related multipulse sequences [20][21][22][23][24][25][26][27] have also been widely employed to mitigate other types of decoherence such as environmental noise fluctuations [28][29][30]. Much work has been done to extend dynamical decoupling to not only preserve the state of the system, but to also cancel errors while performing operations on the system (dynamical gate correction) [31][32][33][34][35][36][37][38][39][40][41][42][43].Although these dynamical decoupling methods have been broadly successful, there are many systems, especially in the context of quantum information technologies, where they exhibit substantial drawbacks. This is because the hig...