scholarly journals Exact energy–time uncertainty relation for arrival time by absorption

2012 ◽  
Vol 45 (18) ◽  
pp. 185301 ◽  
Author(s):  
Jukka Kiukas ◽  
Andreas Ruschhaupt ◽  
Piet O Schmidt ◽  
Reinhard F Werner
Author(s):  
Thomas Beechem ◽  
Samuel Graham

The lifetimes of polar optical phonons are known to affect the electrical and thermal performance of gallium nitride (GaN) based devices. Utilizing the energy-time uncertainty relation, this study investigates these lifetimes using Raman spectroscopy for a series of samples having free carrier concentrations ranging from 1.24e18 to 3e17 cm−3. By measuring across the typical operating temperatures of these devices, the mechanisms responsible for scattering of 5 separate optical modes are elucidated. It is found that phonon-carrier interaction directly determines the lifetime of the polar optical A1(LO) mode while indirectly influencing the modes into which this longitudinal phonon decays, namely, E1 and A1(TO). Thus understanding the entire phonon energy cascade is vital both for management of the so called “hot phonon” effect as well as modeling of carrier-phonon interactions.


1994 ◽  
Vol 50 (2) ◽  
pp. 933-938 ◽  
Author(s):  
Donald H. Kobe ◽  
V. C. Aguilera-Navarro

1997 ◽  
Vol 12 (27) ◽  
pp. 2029-2035 ◽  
Author(s):  
G. Amelino-Camelia ◽  
N. E. Mavromatos ◽  
John Ellis ◽  
D. V. Nanopoulos

Within a Liouville approach to noncritical string theory, we argue for a nontrivial commutation relation between space and time observables, leading to a nonzero space–time uncertainty relation δx δt>0, which vanishes in the limit of weak string coupling.


JETP Letters ◽  
1996 ◽  
Vol 63 (11) ◽  
pp. 924-929 ◽  
Author(s):  
S. N. Molotkov ◽  
S. S. Nazin

2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Noboru Takeichi

In the ground-based arrival time control operation, the measurement of the arrival time error and the speed advisory to cancel it are performed at specific waypoint(s). It is generally recognized that the arrival time accuracy depends on the accuracy of trajectory prediction and control and the availability of information about the aircraft intent. Additionally, the position of the waypoint also determines the arrival time accuracy. Therefore, in this study, the feasibility of waypoint position optimization to improve the arrival time accuracy of aircraft controlled by ground-based speed advisory and its effectiveness are discussed. The models of flight time uncertainty and the arrival time control window were developed using the actual track and numerical weather forecast data. An optimization problem was formulated that defined the arrival time uncertainty at the terminal point as the objective function and numerically solved using sequential quadratic programming. Through numerical investigations, the feasibility of the waypoint position optimization and its effectiveness were clearly demonstrated in comparison with uniform arrangement cases. It was also clarified that the advantage of the multiple waypoint application was enhanced when larger arrival time control windows were available.


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