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Physical Sciences and Mathematics Commons

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Full-Text Articles in Physical Sciences and Mathematics

Pauli Spin Blockade And Lifetime-Enhanced Transport In A Si/Sige Double Quantum Dot, C. B. Simmons, Teck Seng Koh, Nakul Shaji, Madhu Thalakulam, L. J. Klein, Hua Qin, H. Luo, D. E. Savage, M. G. Lagally, A. J. Rimberg Dec 2010

Pauli Spin Blockade And Lifetime-Enhanced Transport In A Si/Sige Double Quantum Dot, C. B. Simmons, Teck Seng Koh, Nakul Shaji, Madhu Thalakulam, L. J. Klein, Hua Qin, H. Luo, D. E. Savage, M. G. Lagally, A. J. Rimberg

Dartmouth Scholarship

We analyze electron-transport data through a Si/SiGe double quantum dot in terms of spin blockade and lifetime-enhanced transport (LET), which is transport through excited states that is enabled by long spin-relaxation times. We present a series of low-bias voltage measurements showing the sudden appearance of a strong tail of current that we argue is an unambiguous signature of LET appearing when the bias voltage becomes greater than the singlet-triplet splitting for the (2,0) electron state. We present eight independent data sets, four in the forward-bias (spin-blockade) regime and four in the reverse-bias (lifetime-enhanced transport) regime and show that all eight …


The Trilinear Hamiltonian: A Zero-Dimensional Model Of Hawking Radiation From A Quantized Source, Paul D. Nation, Miles P. Blencowe Sep 2010

The Trilinear Hamiltonian: A Zero-Dimensional Model Of Hawking Radiation From A Quantized Source, Paul D. Nation, Miles P. Blencowe

Dartmouth Scholarship

We investigate a quantum parametric amplifier with dynamical pump mode, viewed as a zero-dimensional model of Hawking radiation from an evaporating black hole. We derive the conditions under which the spectrum of particles generated from vacuum fluctuations deviates from the thermal spectrum predicted for the conventional parametric amplifier. We find that significant deviations arise when the pump mode (black hole) has emitted nearly half of its initial energy into the signal (Hawking radiation) and idler (in-falling particle) modes. As a model of black hole dynamics, this finding lends support to the view that late-time Hawking radiation contains information about the …


Equilibrium States Of A Test Particle Coupled To Finite-Size Heat Baths, Qun Wei, S. Taylor Smith, Roberto Onofrio Mar 2010

Equilibrium States Of A Test Particle Coupled To Finite-Size Heat Baths, Qun Wei, S. Taylor Smith, Roberto Onofrio

Dartmouth Scholarship

We report on numerical simulations of the dynamics of a test particle coupled to competing Boltzmann heat baths of finite size. After discussing some features of the single bath case, we show that the presence of two heat baths further constrains the conditions necessary for the test particle to thermalize with the heat baths. We find that thermalization is a spectral property in which the oscillators of the bath with frequencies in the range of the test particle characteristic frequency determine its degree of thermalization. We also find an unexpected frequency shift of the test particle response with respect to …