TY - JOUR T1 - Sisyphus Thermalization of Photons in a Cavity-Coupled Double Quantum Dot JF - Physical Review Letters Y1 - 2016 A1 - Michael Gullans A1 - J. Stehlik A1 - Y. -Y. Liu A1 - J. R. Petta A1 - J. M. Taylor AB -

A strongly driven quantum system, coupled to a thermalizing bath, generically evolves into a highly non-thermal state as the external drive competes with the equilibrating force of the bath. We demonstrate a notable exception to this picture for a microwave resonator interacting with a periodically driven double quantum dot (DQD). In the limit of strong driving and long times, we show that the resonator field can be driven into a thermal state with a chemical potential given by a harmonic of the drive frequency. Such tunable chemical potentials are achievable with current devices and would have broad utility for quantum simulation in circuit quantum electrodynamics. As an example, we show how several DQDs embedded in an array of microwave resonators can induce a phase transition to a Bose-Einstein condensate of light.

VL - 117 U4 - 056801 UR - http://arxiv.org/abs/1512.01248 CP - 5 U5 - http://dx.doi.org/10.1103/PhysRevLett.117.056801 ER - TY - JOUR T1 - Injection Locking of a Semiconductor Double Quantum Dot Micromaser JF - Physical Review A Y1 - 2015 A1 - Y. -Y. Liu A1 - J. Stehlik A1 - Michael Gullans A1 - J. M. Taylor A1 - J. R. Petta AB - Emission linewidth is an important figure of merit for masers and lasers. We recently demonstrated a semiconductor double quantum dot (DQD) micromaser where photons are generated through single electron tunneling events. Charge noise directly couples to the DQD energy levels, resulting in a maser linewidth that is more than 100 times larger than the Schawlow-Townes prediction. Here we demonstrate a linewidth narrowing of more than a factor 10 by locking the DQD emission to a coherent tone that is injected to the input port of the cavity. We measure the injection locking range as a function of cavity input power and show that it is in agreement with the Adler equation. The position and amplitude of distortion sidebands that appear outside of the injection locking range are quantitatively examined. Our results show that this unconventional maser, which is impacted by strong charge noise and electron-phonon coupling, is well described by standard laser models. VL - 92 U4 - 053802 UR - http://arxiv.org/abs/1508.04147 CP - 5 U5 - 10.1103/PhysRevA.92.053802 ER - TY - JOUR T1 - Phonon-Assisted Gain in a Semiconductor Double Quantum Dot Maser JF - Physical Review Letters Y1 - 2015 A1 - Michael Gullans A1 - Y. -Y. Liu A1 - J. Stehlik A1 - J. R. Petta A1 - J. M. Taylor AB - We develop a microscopic model for the recently demonstrated double quantum dot (DQD) maser. In characterizing the gain of this device we find that, in addition to the direct stimulated emission of photons, there is a large contribution from the simultaneous emission of a photon and a phonon, i.e., the phonon sideband. We show that this phonon-assisted gain typically dominates the overall gain which leads to masing. Recent experimental data are well fit with our model. VL - 114 U4 - 196802 UR - http://arxiv.org/abs/1501.03499v3 CP - 19 J1 - Phys. Rev. Lett. U5 - 10.1103/PhysRevLett.114.196802 ER - TY - JOUR T1 - Semiconductor double quantum dot micromaser JF - Science Y1 - 2015 A1 - Y. -Y. Liu A1 - J. Stehlik A1 - C. Eichler A1 - Michael Gullans A1 - J. M. Taylor A1 - J. R. Petta AB - The coherent generation of light, from masers to lasers, relies upon the specific structure of the individual emitters that lead to gain. Devices operating as lasers in the few-emitter limit provide opportunities for understanding quantum coherent phenomena, from THz sources to quantum communication. Here we demonstrate a maser that is driven by single electron tunneling events. Semiconductor double quantum dots (DQDs) serve as a gain medium and are placed inside of a high quality factor microwave cavity. We verify maser action by comparing the statistics of the emitted microwave field above and below the maser threshold. VL - 347 U4 - 285 - 287 UR - http://arxiv.org/abs/1507.06359v1 CP - 6219 J1 - Science U5 - 10.1126/science.aaa2501 ER -