- document
-
Friesen, D. (author)Helicopters possess the unique capability of hovering stationary in the air and landing with relative ease in a variety of terrain, which sets them apart from fixed-wing aircraft. However, due to operations close to terrain and obstacles, piloting a helicopter can be a challenging task that involves risk of incidents and accidents. One avenue to...doctoral thesis 2023
- document
-
Losert, Merritt P. (author), Eriksson, M. A. (author), Joynt, Robert (author), Rahman, Rajib (author), Scappucci, G. (author), Coppersmith, Susan N. (author), Friesen, Mark (author)Silicon/silicon-germanium heterostructures have many important advantages for hosting spin qubits. However, controlling the valley splitting (the energy splitting between the two low-lying conduction-band valleys) remains a critical challenge for ensuring qubit reliability. Broad distributions of valley splittings are commonplace, even among...journal article 2023
- document
-
Friesen, D. (author), Borst, C. (author), Pavel, M.D. (author), Masarati, Pierangelo (author), Mulder, Max (author)This paper investigates the effects of different automation design philosophies for a helicopter navigation task. A baseline navigation display is compared with two more advanced systems: an advisory display, which provides a discrete trajectory suggestion; and a constraint-based display, which provides information about the set of possible...journal article 2022
- document
- Bonilla Castro, Johanna (author), Schweiger, Markus (author), Moser, David (author), Tanahashi, Tadanori (author), King, Bruce H. (author), Friesen, Gabi (author), Haitao, Liu (author), French, Roger H. (author), Vogt, M.R. (author) report 2020
- document
-
Kornich, V. (author), Vavilov, Maxim G. (author), Friesen, Mark (author), Eriksson, M. A. (author), Coppersmith, S. N. (author)We study how the shape of a periodic magnetic field affects the presence of Majorana bound states (MBS) in a nanowire-superconductor system. Motivated by the field configurations that can be produced by an array of nanomagnets, we consider spiral fields with an elliptic cross section and fields with two sinusoidal components. We show that MBS...journal article 2020
- document
-
Friesen, D. (author), Pavel, M.D. (author), Borst, C. (author), Stroosma, O. (author), Masarati, Pierangelo (author), Mulder, Max (author)This paper aims to reveal the effect of different display design principles in the helicopter domain. Two different obstacle avoidance support displays are evaluated during low-altitude, forward helicopter flight: a baseline Head-Up Display (HUD) is complemented either by a conventional advisory display, or a constraint-based display inspired by...conference paper 2020
- document
-
Xue, X. (author), D'anjou, Benjamin (author), Watson, T.F. (author), Ward, Daniel R. (author), Savage, Donald E. (author), Lagally, Max G. (author), Friesen, Mark (author), Eriksson, Mark A. (author), Vandersypen, L.M.K. (author)Quantum error correction is of crucial importance for fault-tolerant quantum computers. As an essential step toward the implementation of quantum error-correcting codes, quantum nondemolition measurements are needed to efficiently detect the state of a logical qubit without destroying it. Here we implement quantum nondemolition measurements...journal article 2020
- document
-
Friesen, D. (author), Pavel, M.D. (author), Borst, C. (author), Masarati, Pierangelo (author), Mulder, Max (author)Head-down hover displays and instrument panels theoretically provide all necessary 2ight data information to control low-speed helicopter manoeuvring. However, past experiments have shown that head-down displays can incur high workload, control instability, and even loss of control when used as the sole 2ight data source. This paper...conference paper 2019
- document
-
Neyens, Samuel F. (author), Foote, Ryan H. (author), Thorgrimsson, Brandur (author), Knapp, T. J. (author), McJunkin, Thomas (author), Vandersypen, L.M.K. (author), Amin, Payam (author), Thomas, Nicole K. (author), Clarke, James S. (author), Savage, D. E. (author), Lagally, M. G. (author), Friesen, Mark (author), Coppersmith, S. N. (author), Eriksson, M. A. (author)Atomic-scale disorder at the top interface of a Si quantum well is known to suppress valley splitting. Such disorder may be inherited from the underlying substrate and relaxed buffer growth, but can also arise at the top quantum well interface due to the random SiGe alloy. Here, we perform activation energy (transport) measurements in the...journal article 2018
- document
-
Watson, T.F. (author), Philips, S.G.J. (author), Kawakami, E. (author), Ward, D. R. (author), Scarlino, P. (author), Veldhorst, M. (author), Savage, D. E. (author), Lagally, M. G. (author), Friesen, Mark (author), Coppersmith, S. N. (author), Eriksson, M.A. (author), Vandersypen, L.M.K. (author)Now that it is possible to achieve measurement and control fidelities for individual quantum bits (qubits) above the threshold for fault tolerance, attention is moving towards the difficult task of scaling up the number of physical qubits to the large numbers that are needed for fault-tolerant quantum computing. In this context, quantum-dot...journal article 2018
- document
-
Kawakami, E. (author), Jullien, T.M.J. (author), Scarlino, P. (author), Ward, Daniel R. (author), Savage, Donald E. (author), Lagally, Max G. (author), Dobrovitski, V.V. (author), Friesen, Mark (author), Coppersmith, Susan N. (author), Eriksson, M.A. (author), Vandersypen, L.M.K. (author)The gate fidelity and the coherence time of a quantum bit (qubit) are important benchmarks for quantum computation. We construct a qubit using a single electron spin in an Si/SiGe quantum dot and control it electrically via an artificial spin-orbit field from a micromagnet. We measure an average single-qubit gate fidelity of ∼99% using...journal article 2016
- document
-
Scarlino, P. (author), Kawakami, E. (author), Ward, D.R. (author), Savage, D.E. (author), Lagally, M.G. (author), Friesen, M. (author), Coppersmith, S.N. (author), Eriksson, M.A. (author), Vandersypen, L.M.K. (author)We demonstrate coherent driving of a single electron spin using second-harmonic excitation in a Si/SiGe quantum dot. Our estimates suggest that the anharmonic dot confining potential combined with a gradient in the transverse magnetic field dominates the second-harmonic response. As expected, the Rabi frequency depends quadratically on the...journal article 2015
- document
-
Prance, J.R. (author), Shi, Z. (author), Siimins, C.B. (author), Savage, D.E. (author), Lagally, M.G. (author), Schreiber, L.R. (author), Vandersypen, L.M.K. (author), Friesen, M. (author), Joynt, R. (author), Coppersmith, S.N. (author), Eriksson, M.A. (author)The spin singlet and triplet states of a two-electron double quantum dot can be used to form a logical qubit that combines fast manipulation and a spin readout mechanism. We demonstrate single-shot readout of the two-electron states of a Si/SiGe double quantum dot using a quantum-point-contact charge sensor and spin-to-charge conversion. From...journal article 2012
- document
- Prance, J.R. (author), Shi, Z. (author), Simmons, C.B. (author), Savage, D.E. (author), Lagally, M.G. (author), Schreiber, L.R. (author), Vandersypen, L.M.K. (author), Friesen, M. (author), Joynt, R. (author), Coppersmith, S.N. (author), Eriksson, M.A. (author) conference paper 2012
- document
-
Prance, J.R. (author), Shi, Z. (author), Simmons, C.B. (author), Savage, D.E. (author), Lagally, M.G. (author), Schreiber, L.R. (author), Vandersypen, L.M.K. (author), Friesen, M. (author), Joynt, R. (author), Coppersmith, S.N. (author), Eriksson, M.A. (author)We investigate the lifetime of two-electron spin states in a few-electron Si/SiGe double dot. At the transition between the (1,1) and (0,2) charge occupations, Pauli spin blockade provides a readout mechanism for the spin state. We use the statistics of repeated single-shot measurements to extract the lifetimes of multiple states simultaneously....journal article 2012
- document
-
Friesen, J.C. (author)Soil moisture information is a vital parameter for water resources planning and food production. In particular for West Africa, where income largely depends on rainfed agriculture, reliable information on available soil water is required for modeling and prediction. Over large areas and, specifically, for data scarce regions, satellite soil...doctoral thesis 2008
- document
-
Friesen, J.C. (author), Van Beek, C. (author), Selker, J. (author), Savenije, H.H.G. (author), Van de Giesen, N. (author)A method for measuring whole-tree interception of precipitation is presented which employs mechanical displacement sensors to measure trunk compression caused by the water captured by the tree. This direct and nondestructive method is demonstrated to be sensitive to less than 5 kg of interception field tests in Netherlands and Ghana.journal article 2008
- document
-
Friesen, J. (author), Rodgers, C. (author), Oguntunde, P.G. (author), Hendrickx, J.M.H. (author), Van de Giesen, N. (author)In West Africa, which is an extremely moisturelimited region, soil water information plays a vital role in hydrologic and meteorologic modeling for improved water resource planning and food security. Recent and upcoming satellite missions, such as SMOS and MetOp, hold promise for the regional observation of soil moisture. The resolution of the...journal article 2008
- document
-
Jeu, Richard A.M. (author), Wagner, W. (author), Holmes, T. R.H. (author), Dolman, A. J. (author), van de Giesen, N.C. (author), Friesen, J (author)Within the scope of the upcoming launch of a new water related satellite mission (SMOS) a global evaluation study was performed on two available global soil moisture products. ERS scatterometer surface wetness data was compared to AMSR-E soil moisture data. This study pointed out a strong similarity between both products in sparse to moderate...journal article 2008
- document
-
Hendrickx, J.M.H. (author), Hong, S. (author), Friesen, J. (author), Compaore, H. (author), Van de Giesen, N.C. (author), Rodgers, C. (author), Vlek, P.L.G. (author)Accurate information on the distribution of sensible and latent heat fluxes as well as soil moisture is critical for evaluation of background characteristics. Since these fluxes are subject to rapid changes in time and space, it is nearly impossible to determine their spatial and temporal distributions over large areas from ground measurements...conference paper 2006