Topological photonics could impact the scalability of integrated photonics, but it has shown limited reconfigurability to date. Here, the authors demonstrate reprogrammable integrated photonics as a nearly universal platform for topological models.
Archaeologists measured the magnetic fields found in clay bricks to determine the construction date of Babylon’s Ishtar Gate.
Radar altimeters are the sole indicators of altitude above a terrain. Spectrally adjacent 5G cellular bands pose significant risks of jamming altimeters and impacting flight landing and takeoff. As wireless technology expands in frequency coverage and utilizes spatial multiplexing, similar detrimental radio-frequency (RF) interference becomes a pressing issue.
To address this interference, RF front ends with exceptionally low latency are crucial for industries like transportation, health care, and the military, where the timeliness of transmitted messages is critical. Future generations of wireless technologies will impose even more stringent latency requirements on RF front-ends due to increased data rate, carrier frequency, and user count.
Additionally, challenges arise from the physical movement of transceivers, resulting in time-variant mixing ratios between interference and signal-of-interest (SOI). This necessitates real-time adaptability in mobile wireless receivers to handle fluctuating interference, particularly when it carries safety-to-life critical information for navigation and autonomous driving, such as aircraft and ground vehicles.
Kim, SW., Wang, K., Chen, S. et al. On the dynamical stability of copper-doped lead apatite. npj Comput Mater 10, 16 (2024). https://doi.org/10.1038/s41524-024-01206-9
Quantum engineering, a dynamic discipline bridging the fundamentals of quantum mechanics and established engineering fields has developed significantly in the past few decades. Two-level systems such as superconducting quantum bits are the building blocks of quantum circuits. Qubits of this type are currently the most researched and used in quantum computing applications1,2,3,4,5. The characteristics of the superconducting qubits such as eigen energies, non-linearity, coupling strengths etc. can be tailored easily by adjusting the design parameters6,7. Qubits have large non-linearity, which makes it possible to selectively address and control them1,3,7,8. This dynamic property makes superconducting qubits a strong candidate for plethora of applications. Other two-level microscopic quantum systems9,10,11,12,13,14 also have certain advantages and may be used in the future.
Quantum devices operate at low temperatures and require good isolation from external noises. Microwave devices, such as circulators and isolators, protect quantum circuits by unidirectionally routing the output signal, whilst simultaneously isolating noise from the output channel back to the quantum circuit. Their non-reciprocal character relies on the properties of ferrites15,16,17. Ferrite-based non-reciprocal devices are bulky15,16,17, and they cannot be positioned near the quantum circuit because they require strong magnetic fields. Although commercial ferrite based non-reciprocal devices harness high isolation and low insertion loss, their dependency on magnetic components limits the scalability of cryogenic quantum circuits15,16,18,19. Various ferrite-free approaches based on non-linear behavior of artificial atoms16, dc superconducting quantum interference devices (dc-SQUID)20,21, and arrays of Josephson junctions (JJ’s)19,22,23,24, have been experimentally demonstrated and implemented. Recently, a circuit based on semiconductor mixers has been used to realize a compact microwave isolator, which the authors claim could be extended to an on-chip device using Josephson mixers, although the “on-chip” demonstration is not yet reported25. Additionally, mesoscopic circulators exploiting the quantum Hall effect to break time-reversal symmetry of electrical transport in 2D systems are explored at a cost of larger magnetic fields deleterious to superconducting circuits18,26,27,28,29. More recently, a passive on-chip circulator based on three Josephson elements operating in charge-sensitive regime was demonstrated30. Such devices are frequently limited by their parameter regime, leaving them charge sensitive and therefore difficult to implement in a practical scenario. However, it is possible to mitigate the charge-sensitivity by carefully tuning the device parameters. Our device operates in a parameter regime that is not sensitive to charge fluctuations or charge parity switching, a fundamental requirement for any practical implementation, and requires small magnetic field. The reported device is a proof of concept (PoC), potentially useful in the applications relevant to microwave read-out components in the field of superconducting quantum circuits.
In this work, we present a robust and simple on-chip microwave diode demonstrating transmission rectification based on a superconducting flux qubit8. The concept of the device is shown in Fig. 1a. The flux qubit is inductively coupled to two superconducting resonators of different lengths with different coupling strengths. The design details are reported later in this section. Probing the qubit at the half-flux (degeneracy point) with one tone-spectroscopy, we observe identical patterns of transmission coefficient for signals propagating in the opposite directions, which are shifted by 5 dB in power. This shift indicates the non-reciprocal behaviour in our device, expressed in terms of transmission rectification ratio ® in this article. The origin of this effect is the non-linearity of the flux qubit, which controls the transmission coefficient of the whole structure.
New findings from the James Webb Space Telescope reveal a surprising abundance of oxygen in the early Universe. Researchers discovered that oxygen levels in galaxies surged within 500–700 million years following the Universe’s birth, reaching levels comparable to those in contemporary galaxies. This suggests that the essential elements for life were present much earlier than previously believed.
In the early Universe, shortly after the Big Bang, only light elements such as hydrogen, helium, and lithium existed. Heavier elements like oxygen were subsequently formed through nuclear fusion reactions within stars and dispersed into galaxies, primarily through events like supernova explosions. This ongoing process of element synthesis, unfolding over the vast expanse of cosmic history, created the diverse elements that constitute the world and living organisms around us.
Astronomers have proposed a new way to solve the so-called “Hubble tension,” but the approach ultimately raises more questions than it answers.
By way of background, cosmologists are in a bit of a crisis these days. One of the most important numbers they can measure is the so-called Hubble constant, the rate of expansion of the present-day universe. At their disposal cosmologists have two sets of tools to measure this number. On one side are tools that probe the relatively nearby universe, like measuring the brightnesses of a certain kind of exploding star known as Type 1a supernovae. These supernovae all erupt with the same absolute brightness, so by measuring their observed magnitudes, astronomers can calculate their distances, and then use that to estimate how quickly the universe is expanding.
The downside of this approach is that supernovae don’t always explode with exactly the same brightness, and for the kind of precision measurements astronomers are aiming for, they have to include assumptions and modeling of supernovae, which can potentially introduce inaccuracies.
I’ve been diving into this cool concept called gravitational time dilation, and it’s like this mind-bending thing predicted by Albert Einstein in his theory of relativity. This concept highlights the actual difference in elapsed time between events observed by individuals situated at varying distances from a massive gravitational source.
If you’re hanging out close to a massive gravitational source, like a planet or star, time slows down for you. It’s like a cosmic slow-motion effect. But if you move away from it, time speeds up. This has been proven in experiments with atomic clocks placed at different heights — the closer to the Earth’s surface, the slower the clock ticks compared to those higher up.
Einstein first talked about this in 1907 when he was figuring out special relativity in speedy frames of reference. In general relativity, it’s like time is doing a dance based on where you are in space, as described by this thing called a metric tensor.
A new study by Dr Constantine Evans of Maynooth University and researchers at the University of Chicago and California Institute of Technology, published in Nature, shows how the molecules that build structures can do both the thinking and the doing.
We tend to separate the brain and muscle – the brain does the thinking; the muscle does the doing. The brain takes in complex information about the world, makes decisions, while muscle merely executes.
This brain-muscle separation has also shaped how we think about the working within a single cell; some molecules within cells are seen as ‘thinkers’ that take in information about the chemical environment and decide what the cell needs to do for survival; separately, other molecules are seen as the ‘muscle’, building structures needed for survival.
As one of the few schools on Long Island offering the AP Capstone program in their curricula, Patchogue-Medford High School provides various STEM opportunities for its students.
From Brookhaven National Laboratory to Stony Brook University right at our fingertips, the possibilities are endless. For instance, on December 8 th, four AP Research students joined Dr. Gatz in spending the day at Cold Spring Harbor Laboratory to conduct the necessary experiments for their research papers.
Senior, Carlo Costigliola, and Junior, Isaac Varghese, have decided to focus their research on DNA barcoding. According to International Barcode of Life, “DNA barcoding is a method of specimen identification using short, standardized segments of DNA.”
