Department of Applied Physics

Description

Nanoscience and Quantum Engineering

The goal of our Large-Scale Integrated Photonics Group research program at HP Laboratories is to build upon many of the breakthroughs made under our prior work in optics to accelerate developments in photonic integrated circuits for high-performance classical and quantum computing. Our ultimate objective is to establish the foundations of a highly scalable and cost-effective “Moore’s Law” for information bandwidth at all levels of granularity from the chip to the enterprise in computer systems. For example, in the context of research and development of an Intelligent Infrastructure for future computing systems, we envision an exascale datacenter using nanophotonic interconnects with performance per unit cost a factor of 20 above that available from the best possible electronic interconnects over distance scales of 1 mm–100 m. We are pursuing several critical technological breakthroughs needed to bring the full benefit of this approach to future commercial computer systems, including hybrid silicon/III-V microring lasers for CWDM data links; nonperiodic subwavelength gratings for planar free-space optical elements, such as mirrors, lenses, and couplers; and CMOS-compatible active and passive photonic components designed to generate, guide, filter, modulate, and detect light in terabit-class DWDM optical waveguides. However, even optical interconnects will not solve the problem of power dissipation in modern CMOS integrated circuits, since it is unlikely that charge-based Group IV transistors can operate reliably with transition energies less than ~1000 kT. Instead, high-performance classical computing based on nanoscale quantum-engineered devices fabricated in architectures that enable reversible computing may allow significant reductions in the power consumed by the global information technology infrastructure. To this end, we are pursuing nanophotonics as a mechanism for strong coherent coupling between single quantum objects such as nitrogen-vacancy color centers in diamond.

Selected Publications

• Coherent Population Trapping of Single Spins in Diamond under Optical Excitation
• Nanoelectronic and Nanophotonic Interconnect
• Silicon microring resonators with 1.5-µm radius
• Devices and architectures for photonic chip-scale integration
• Hybrid photonic crystal cavity and waveguide for coupling to diamond NV-centers
• Electrically-pumped compact hybrid silicon microring lasers for optical interconnects
• Observation of the Dynamic Jahn-Teller Effect in the Excited States of Nitrogen-Vacancy Centers in Diamond
• Conversion of neutral nitrogen-vacancy centers to negatively charged nitrogen-vacancy centers through selective oxidation
• Flat Dielectric Grating Reflectors with Focusing Abilities
• Nanophotonics for Quantum Optics Using Nitrogen-Vacancy Centers in Diamond