Optically Pumped AlGaN Double Heterostructure Deep-UV Laser by Molecular Beam Homoepitaxy: Mirror Imperfections and Cavity Loss

Kavli Affiliate: Grace Xing | First 5 Authors: Len van Deurzen, Ryan Page, Vladimir Protasenko, Huili, Xing | Summary: We demonstrate the first optically pumped sub-300 nm UV laser structures grown by plasma-assisted molecular beam epitaxy on single-crystal bulk AlN. The edge-emitting laser structures fabricated with the AlN/AlGaN heterostructures exhibit multi-mode emission with peak gain […]


Continue.. Optically Pumped AlGaN Double Heterostructure Deep-UV Laser by Molecular Beam Homoepitaxy: Mirror Imperfections and Cavity Loss

Superconductivity in a quintuple-layer square-planar nickelate

Kavli Affiliate: Lena F. Kourkoutis | First 5 Authors: Grace A. Pan, Dan Ferenc Segedin, Harrison LaBollita, Qi Song, Emilian M. Nica | Summary: Since the discovery of high-temperature superconductivity in the copper oxide materials, there have been sustained efforts to both understand the origins of this phase and discover new cuprate-like superconducting materials. One […]


Continue.. Superconductivity in a quintuple-layer square-planar nickelate

Infrared dielectric functions and Brillouin zone center phonons of $α$-Ga$_2$O$_3$ compared to $α$-Al$_2$O$_3$

Kavli Affiliate: Debdeep Jena | First 5 Authors: Megan Stokey, Rafal Korlacki, Matthew Hilfiker, Sean Knight, Steffen Richter | Summary: We determine the anisotropic dielectric functions of rhombohedral $alpha$-Ga$_2$O$_3$ by far-infrared and infrared generalized spectroscopic ellipsometry and derive all transverse optical and longitudinal optical phonon mode frequencies and broadening parameters. We also determine the high […]


Continue.. Infrared dielectric functions and Brillouin zone center phonons of $α$-Ga$_2$O$_3$ compared to $α$-Al$_2$O$_3$

Dipolar excitonic insulator in a moire lattice

Kavli Affiliate: Jie Shan | First 5 Authors: Jie Gu, Liguo Ma, Song Liu, Kenji Watanabe, Takashi Taniguchi | Summary: Two-dimensional (2D) moire materials provide a new solid-state platform with unprecedented controllability for studies of correlated quantum phenomena. To date, experimental studies have focused on the correlated electronic states; the correlated bosonic states in moire […]


Continue.. Dipolar excitonic insulator in a moire lattice

A Resolution-Adaptive 8 mm$^text{2}$ 9.98 Gb/s 39.7 pJ/b 32-Antenna All-Digital Spatial Equalizer for mmWave Massive MU-MIMO in 65nm CMOS

Kavli Affiliate: Alyosha Molnar | First 5 Authors: Oscar Castañeda, Zachariah Boynton, Seyed Hadi Mirfarshbafan, Shimin Huang, Jamie C. Ye | Summary: All-digital millimeter-wave (mmWave) massive multi-user multiple-input multiple-output (MU-MIMO) receivers enable extreme data rates but require high power consumption. In order to reduce power consumption, this paper presents the first resolution-adaptive all-digital receiver ASIC […]


Continue.. A Resolution-Adaptive 8 mm$^text{2}$ 9.98 Gb/s 39.7 pJ/b 32-Antenna All-Digital Spatial Equalizer for mmWave Massive MU-MIMO in 65nm CMOS

A Resolution-Adaptive 8 mm$^text2$ 9.98 Gb/s 39.7 pJ/b 32-Antenna All-Digital Spatial Equalizer for mmWave Massive MU-MIMO in 65nm CMOS

Kavli Affiliate: Alyosha Molnar | Summary:All-digital millimeter-wave (mmWave) massive multi-user multiple-input multiple-output (MU-MIMO) receivers enable extreme data rates but require high power consumption. In order to reduce power consumption, this paper presents the first resolution-adaptive all-digital receiver ASIC that is able to adjust the resolution of the data-converters and baseband-processing engine to the instantaneous communication […]


Continue.. A Resolution-Adaptive 8 mm$^text2$ 9.98 Gb/s 39.7 pJ/b 32-Antenna All-Digital Spatial Equalizer for mmWave Massive MU-MIMO in 65nm CMOS

Resolution-Adaptive All-Digital Spatial Equalization for mmWave Massive MU-MIMO

Kavli Affiliate: Alyosha Molnar | First 5 Authors: Oscar Castañeda, Seyed Hadi Mirfarshbafan, Shahaboddin Ghajari, Alyosha Molnar, Sven Jacobsson | Summary: All-digital basestation (BS) architectures for millimeter-wave (mmWave) massive multi-user multiple-input multiple-output (MU-MIMO), which equip each radio-frequency chain with dedicated data converters, have advantages in spectral efficiency, flexibility, and baseband-processing simplicity over hybrid analog-digital solutions. […]


Continue.. Resolution-Adaptive All-Digital Spatial Equalization for mmWave Massive MU-MIMO

Resolution-Adaptive All-Digital Spatial Equalization for mmWave Massive MU-MIMO

Kavli Affiliate: Alyosha Molnar | Summary:All-digital basestation (BS) architectures for millimeter-wave (mmWave) massive multi-user multiple-input multiple-output (MU-MIMO), which equip each radio-frequency chain with dedicated data converters, have advantages in spectral efficiency, flexibility, and baseband-processing simplicity over hybrid analog-digital solutions. For all-digital architectures to be competitive with hybrid solutions in terms of power consumption, novel signal-processing […]


Continue.. Resolution-Adaptive All-Digital Spatial Equalization for mmWave Massive MU-MIMO

A variational approximate posterior for the deep Wishart process

Kavli Affiliate: Christopher Ober| First 5 Authors: Sebastian W. Ober, Sebastian W. Ober, , , | Summary:Recent work introduced deep kernel processes as an entirely kernel-based alternative to NNs (Aitchison et al. 2020). Deep kernel processes flexibly learn good top-layer representations by alternately sampling the kernel from a distribution over positive semi-definite matrices and performing […]


Continue.. A variational approximate posterior for the deep Wishart process

High conductivity Polarization-induced 2D hole gases in Undoped GaN/AlN Heterojunctions enabled by Impurity Blocking Layers

Kavli Affiliate: Grace Xing | First 5 Authors: Reet Chaudhuri, Zhen Chen, David Muller, Huili Grace Xing, Debdeep Jena | Summary: High-conductivity undoped GaN/AlN 2D hole gases (2DHGs), the p-type dual of the AlGaN/GaN 2D electron gases (2DEGs), have offered valuable insights into hole transport in GaN and enabled the first GaN GHz RF p-channel […]


Continue.. High conductivity Polarization-induced 2D hole gases in Undoped GaN/AlN Heterojunctions enabled by Impurity Blocking Layers