Quantum materials, a fascinating class of materials that harness the power of quantum mechanics, are revolutionizing modern science and technology. Quantum materials often possess exotic states of matter, such as superconductivity or magnetic ordering, that defy conventional understanding and can be manipulated for various technological applications. To further enhance and manipulate the intriguing characteristics of quantum materials, researchers leverage nanostructuring—the ability to precisely control the geometry on the atomic scale. Specifically, nanostructuring provides the ability to manipulate and fine-tune the electrical and thermal properties of quantum and other materials. This can result, for example, in designer structures that conduct current very well, but impede heat transport. These structures can help recapture and utilize waste heat in electronics, buildings, and vehicles—enhancing their efficiency and, thereby, reducing power consumption. A related critical challenge for a broad range of nanotechnologies is the need for more efficient cooling, so that the nano devices do not overheat during operation. To better understand heat transport at the nanoscale, JILA Fellows Margaret Murnane, Henry Kapteyn, and their research groups within the STROBE NSF Center, JILA and the University of Colorado Boulder, created the first general analytical theory of nanoscale-confined heat transport, that can be used to engineer heat transport in 3D nanosystems—such as nanowires and nanomeshes—that are of great interest for next-generation energy-efficient devices. This discovery was published in NanoLetters.