Decoding Quantum Technologies: Sensing, Communications, and Computing
When we talk about quantum technologies, we refer to a set of advanced disciplines that harness the unique properties of quantum mechanics, such as state superposition, interference, and quantum entanglement. These technologies include quantum sensing and metrology, which allow for measurements with unprecedented precision; quantum communications, which promise unbreakable security in data transmission; and quantum computing and simulation, which have the potential to solve complex problems that are beyond the reach of classical computers. In this blog, we delve into what these technologies are, what they are based on, and their potential to generate a transformative impact on our lives.
This family of quantum technologies is linked by a fundamental common element: the use of different energy levels in a physical platform—such as electrons in a material, photons (individual particles of light), or other natural systems—to encode information. For example, electrons in an atom can be found in orbitals closer to or farther from the nucleus, and each position corresponds to a different energy level. When excited by absorbing light, electrons jump to a higher energy level; when this energy decays, they return to their original state. The ability to individually control these energy transitions allows them to be used for information storage, which constitutes the basis of the so-called qubits. A lower energy state can be considered a 0, while a higher energy state may be interpreted as a 1.
A fundamental aspect of quantum mechanics is that it is not possible to know exactly what state a physical system is in during the process of interaction and control—except at the moment of measurement. Therefore, the physical system or qubit is considered to be in a superposition state until the measurement projects it onto one energy level or another. Thus, statistically, multiple measurements may yield different results, and the exact outcome is the result of considering multiple measurements.
This principle of superposition opens the door to countless different outcomes—not only 0s or 1s, but also results that combine various proportions of both. If we imagine multiple particles and measure their final states, the number of possible combinations would be overwhelmingly vast due to the interference between all statistical combinations. It is important to note that once a measurement is made, the quantum superposition is destroyed, and the final state—either 0 or 1—is determined, making it impossible for the system to return to a superposition state.
Quantum Entanglement
Additionally, it has been demonstrated that quantum particles—such as photons, electrons, or atoms—can interact and generate what is known as quantum entanglement, whereby their interaction causes their states to become connected. This phenomenon is especially relevant in communications: two entangled particles enable the transmission of information over long distances. If we measure a 0 or 1 in one particle at a specific location, a second entangled particle at a distant location will instantly yield the corresponding reciprocal information. This is a powerful phenomenon because it allows information to be transmitted at a distance without destroying the quantum superposition of both particles—by measuring one, we immediately know the state of its entangled counterpart.
In the past, we experienced the First Quantum Revolution, during which the fundamental physical principles of quantum mechanics were deeply studied and began to be applied in technologies that have profoundly shaped our daily lives, such as semiconductors—the basis of electronics and devices like transistors, lasers, and photovoltaic cells. Today, we are immersed in what is known as the Second Quantum Revolution, in which the level of control over quantum processes using high-precision instrumentation is so advanced that we can use elements of nature to create a new generation of quantum technologies with extraordinary disruptive potential, ushering in a paradigm shift in fields like metrology, communications, and computing.
Quantum Sensing
The aforementioned qubits offer great stability, and their energies can be precisely controlled using high-precision instrumentation. Therefore, any external influence on a qubit may alter its energy level. As a result, these physical platforms can be employed as measurement devices or quantum sensors, detecting the fingerprint of any external signal. Quantum sensing or metrology is revolutionizing the precision of scientific measurements, enabling more accurate control because of the unmatched precision with which quantum object energies are known. This opens the door to monitoring a wide array of external disturbances of different natures—electromagnetic, mechanical, gravitational, thermal, etc. Additionally, advances in measurement technologies, combined with the ability to detect changes in individual quantum particles, allow for detection with unprecedented sensitivity. This extraordinary sensitivity and specificity, along with superior precision and non-invasiveness, are transforming the field of biomedicine. Quantum sensors can detect minute variations in physical or chemical characteristics and distinguish between closely related molecules or signals, significantly enhancing both accuracy and sensitivity and broadening the horizons of biomedical diagnostics.
For instance, a quantum sensor can detect signals and impulses produced by a single neuron in the brain with spatial resolution at the subcellular level. This unique capability makes them promising tools for a wide range of applications in medicine, chemistry, and pharmaceuticals, as well as in energy, environmental monitoring, logistics, transportation, space exploration, and defense.
The applications of quantum sensing are vast, and its impact on our lives is profound. For example, quantum gravimetry is being used to detect oil deposits by probing the subsoil without drilling. In scientific research and climatology, quantum sensors offer an unprecedented leap in monitoring our planet and its changes, while in navigation, they allow for maintaining course without relying on external references. In biomedical research, quantum sensors offer new methodologies for high-precision, less invasive nuclear magnetic resonance. In telecommunications, quantum metrology allows the detection of radio signals that traditional sensors cannot perceive, opening a wide range of possibilities across multiple sectors. High-precision atomic clocks have refined the time unit standard and are already being used for synchronization in high-precision communications, making them essential for GPS communications.
At Gradiant, we work with various quantum sensing technologies and platforms, from laser-controlled atomic systems for detecting radio frequency signals in defense and telecommunications, to platforms based on synthetic diamond defects integrated into chips capable of monitoring thermal, magnetic, or radioelectric properties. The overarching goal of our projects is to generate quantum hardware technologies for various metrological applications and validate their effectiveness in relevant operational environments, bringing these technologies closer to innovative real-world uses. Some of these projects include Quantum Cognitive Digital Industry, 6G Diferente, PROPHET, and DIAMONITRO AIE.
Quantum Communications: Quantum Key Distribution (QKD)
In the field of quantum communications, the scientific and technological community is working tirelessly to create networks for distributing information generated and transmitted using individual and entangled photons. This set of encrypted data transmission techniques is called Quantum Key Distribution (QKD), and it leverages the quantum principles of entanglement and superposition to create a completely secure communication system. The information encoded in light photons in quantum qubit states (entangled) is transmitted through communication channels such as optical fiber, free-space ground-to-satellite, or satellite-to-satellite links, and is theoretically impossible to intercept without detection. This is because any attack by an external agent would collapse the quantum state through unauthorized observation, alerting the owners of the communication channel to third-party interference. This makes quantum communications undecipherable and particularly attractive to sectors requiring high levels of security, such as government departments, financial institutions, and defense organizations.
The rising concerns around cybersecurity are accelerating the development of quantum cryptography. Conventional cryptographic methods are becoming increasingly vulnerable to quantum-based attacks, highlighting the urgent need for more secure alternatives. In this context, quantum cryptography—particularly Quantum Key Distribution (QKD)—emerges as an effective solution by leveraging fundamental principles of quantum mechanics to establish secure communication channels.
The growing sophistication and frequency of cyberattacks, along with the vulnerability of RSA-type cryptographic algorithms to emerging technologies such as quantum computing, have exposed the limitations of traditional cryptographic systems. This has led governments and organizations to research and invest in technologies capable of withstanding quantum threats. This increasing concern for cybersecurity is significantly driving progress in quantum cryptography and steering the industry toward the development of communication techniques that offer robust and fundamentally secure protection.
At Gradiant, we work to develop and mature various technological aspects of quantum communications. On the one hand, we integrate quantum communications hardware into communication networks such as 5G networks to ensure their security. We also design optoelectronic reception systems for detecting quantum communication channels in ground-to-satellite and satellite-to-satellite links, as well as Key Management Systems (KMS) for the secure use of these keys. In order to extend the use of QKD protocols to long-distance communications and networks, Gradiant develops physical-quantum hardware capable of acting as repeaters for quantum communications, enabling signal regeneration without compromising security. This includes the use of entangled photon sources and protocols that allow the establishment of secure links over long distances, overcoming the limitations of direct transmission. Gradiant’s activity in quantum communications has a clear technological objective: to ensure the security of critical infrastructures by providing them with quantum-proof technologies.
Quantum Computing and Simulation
Quantum computing, in turn, has the potential to revolutionize the way we solve complex problems. Unlike classical computers, which process information in binary bits (0 or 1), quantum computers use qubits, which can exist in multiple states simultaneously thanks to the phenomenon of quantum superposition. This ability allows quantum computers to perform parallel calculations, solving problems that would take current technologies centuries to complete in just a matter of seconds.
One of the most disruptive areas within this field is quantum simulation, where the very nature of the quantum-physical system is used to map mathematical problems and observe their evolution toward a stable solution. This enables the solution of complex numerical problems in fractions of a second, whereas classical computing would require supercomputers or might not be capable of solving them at all. On the other hand, the controlled use of individual qubits to implement quantum gates allows for the execution of specific quantum computing algorithms on different types of quantum processors.
Quantum computing stands out for its capacity to tackle combinatorial and optimization problems, as well as its potential to factor and decrypt cryptographic algorithms such as RSA. This opens the door to the development of new cryptography (alongside the previously mentioned QKD), including more powerful and quantum-resistant classical algorithms, encompassed within the field of post-quantum cryptography. Additionally, quantum computing offers impactful applications in sectors such as logistics optimization across various domains, materials or drug simulation, genetic analysis, and artificial intelligence—with the emergence of so-called Quantum Machine Learning (QML).
A recent report by Globant on technology trends for 2024 reveals that the quantum computing market is experiencing dramatic growth, projected to increase from $866 million in 2023 to $4.375 billion by 2028, with an annual growth rate of 38.3%. This remarkable growth not only highlights the rising importance of quantum technologies but also opens new opportunities to enhance machine learning and artificial intelligence systems, ushering in a new era that promises to redefine cybersecurity, telecommunications, and computing on a global scale.
Quantum computers, with their unique ability to use qubits instead of traditional bits, enable calculations with unprecedented speed and precision. This makes them especially well-suited for applications requiring the processing of vast amounts of data, such as medical research, logistics optimization, and cybersecurity.
For instance, pharmaceutical company Merck estimates that quantum computing could reduce drug development times by 20%, which would have a significant impact on the healthcare industry. Similarly, DHL projects that route optimization and simultaneous goods packaging will greatly benefit from the capabilities of this technology. The implementation of quantum computing is not limited to a single sector; its potential to revolutionize industries is virtually limitless—ranging from cryptography to DNA research, and from chemistry to banking.
At Gradiant, we research and develop quantum computing algorithms capable of delivering new solutions across different sectors, with a particular focus on applications in telecommunications, image processing, and multivariable system optimization. Gradiant leads the QUORUM project, funded by the Centre for the Development of Industrial Technology (CDTI) under the Cervera Innovation Ecosystems program, aiming to generate knowledge in the field of quantum computing and its applications, facilitate technology transfer to the business sector, and train new talent.
El panorama de las tecnologías cuánticas
The Quantum Technology Landscape
After exploring the main quantum technologies and their remarkable applications—from sensing to quantum computing—it’s clear that we are only at the beginning of a technological revolution. Each breakthrough we’ve discussed—whether in measurement precision, communication security, or the processing power of quantum computers—is opening up a range of possibilities that will transform industries such as healthcare, logistics, energy, and more.
But how is Europe positioning itself in this field amid growing international competition? What actions are governments and companies taking to lead this revolution? In our next article, we will take a closer look at the national, European, and international landscape, analyzing the advancements and challenges that will shape the future of quantum technologies. Stay tuned!
QUORUM: Proyecto Financiado por la Unión Europea – Next Generation EU y el Plan de Recuperación, Transformación y Resiliencia
QKD: Financiado con cargo al Mecanismo de Recuperación y Resiliencia (MRR), en el marco del Plan de Recuperación, Transformación y Resiliencia (PRTR).
