Q-CTRL is a global provider of quantum control infrastructure software with a stated goal to make quantum useful. Toward that end, the company recently announced the creation of a new quantum sensing division that will be led by Dr. Russell Anderson. 

Prior to his earlier assignments with Q-CTRL, Dr. Anderson was with La Trobe University, School of Molecular Sciences, in Victoria, Australia. He obtained his Bachelor of Science in Physics and Pure Mathematics from The University of Western Australia and his PhD from the Swinburne University of Technology.

Dr. Anderson and an initial team of 15 scientists have a mission to develop new generations of ultrasensitive quantum sensors using Q-CTRL’s quantum control software along with other technologies. 

Most of today’s media coverage is about quantum computing, however quantum sensing is equally important. Quantum sensors depend on quantum mechanical properties such as atomic energy levels, varying photonic levels, photonic states, and spins of subatomic particles. These technologies make quantum sensors ultra-sensitive to infinitesimally weak changes in its environment and provide information about the sources of those changes. The use of these atomic properties also makes the sensors very *stable* over time, because the signal comes from the rules of quantum. 

Q-CTRL plans to explore new modes of quantum sensors using its expertise in advanced software, AI, and signal processing. In particular, it is focused on how robust control and feedback can be used to stabilize quantum sensors against the common sources of degradation experienced in real field settings outside of the laboratory. The company believes there is a large market for quantum sensors in the areas of defense, PNT (positioning, navigation, and timing), mineral exploration, magnetic anomaly detection, climate monitoring, long-term weather forecasting, and space exploration.

For example, software-enhanced quantum gravity sensors could image subterranean mineral deposits or even discover new underground water flows. Highly sensitive quantum accelerometers could also be used as navigation aids in locations where GPS might be unavailable or in the event of a catastrophic GPS failure.

Types of quantum sensors

Here are common types of quantum sensors:

• An atomic clock is a quantum sensor. It has hundreds of uses such as GPS navigation, the internet, cell phone calls, and others.
• Atom interferometers are used as gravimeters and gravity gradiometers to study physical aspects of the earth such as volcanos, groundwater, mineral deposits, tidal dynamics, and information about what exists beneath the polar ice caps.
• Optical magnetometers use atomic spins in vapors, Bose-Einstein condensates, and nitrogen vacancies in solid states. These devices allow mapping applications and navigation locally and at a distance. Q-CTRL uses these to identify and localize emitters in the RF for defense purposes. This was the subject of its Army Quantum Technology Challenge demonstration.
• Another solid-state device is a Superconducting Quantum Interference Device (SQUID). These are most commonly used in medical applications.
• Quantum optical effects can be used for microscopy, spectroscopy, and interferometry. For example, the National Science Foundation uses squeezed light in its Laser Interferometer Gravitational-Wave Observatory (LIGO) to detect collisions between black holes.
• Quantum electric field sensors rely on Rydberg atoms that are created by injecting extra energy into an atom causing the orbit of the outer-most electron to expand, increasing its sensitivity to changes in electromagnetic fields. A Rydberg quantum sensor could be used as an ultra-sensitive broadband receiver or antenna and replace those shown in the photo above. 

Army QTC demonstration

Q-CTRL recently had the opportunity to provide a public demonstration of one of its quantum sensing capabilities at the Australian Army Quantum Technology Challenge(QTC) in Adelaide, Australia. 

According to the Australian Army website, the QTC is an annual series of events that see teams of Australia's world-leading quantum scientists and engineers competing to show how quantum technologies can solve important Army problems and deliver unprecedented capabilities. 

Q-CTRL's task at the QTC challenge was to locate electromagnetic emitters operating within a defined simulated battlespace. The Australian Army looked to the demonstration results to determine if quantum sensors can detect, locate and identify electromagnetic emitters with greater precision, range and bandwidth.

Funds from the Army QTC are part of the $60M of publicly disclosed contracts that have previously been awarded to Q-CTRL’s sensing team and its partners over the last 18 months by the Australian government. These include a project with Advanced Navigation as Q-CTRL’s partner on a hybrid classical-quantum inertial navigation system. Additional project funding for space-qualified quantum sensors included a grant from Cooperative Research Centres Projects and funding from the Modern Manufacturing Initiative. 

Complexity of Q-CTRL hardware for the QTC

The quantum sensing magnetometer that Q-CTRL demonstrated at the Army QTC used warm vapor cells and an optical pump probe technique previously developed by four members of the Q-CTRL team. Their prior research happened to be particularly well-suited for the Army QTC demonstration. 

The Army QTC challenge required Q-CTRL's quantum sensors to identify signatures that could potentially be transmitted from unmanned land, air, or undersea vehicles, a scenario where many emission frequencies are in the hundreds of kilohertz. To meet this challenge, Q-CTRL researchers developed quantum sensors with an instantaneous bandwidth of one megahertz and with the capability to detect signals emitted in that range of radio frequencies.

Dr. Michael Biercuk, Professor of Quantum Physics and Quantum technology at the University of Sydney and the CEO and Founder of Q-CTRL, said the ARMY QTC demonstration was very successful and Q-CTRL met all requirements of the challenges. 

"A high instantaneous bandwidth was a key feature needed for the demonstration," Dr. Biercuk said. "That allows us to modulate a signal in the time and frequency domains and read those signals out directly. The team had previously demonstrated that capability several years ago and published a research paper on the results. However, the QTC demonstration required us to add a real-time localization algorithm combining signals from multiple magnetometers."

Dr. Biercuk further explained that in addition to detecting an emitter’s signature, the team also needed to locate the emitter as well as identify it. The four-corner magnetometer array served that purpose. To determine differences in signals received at each of the four magnetometers, an FPGA was used to calculate the emitter’s real-time location. 

Dr. Biercuk pointed out another important reason he believed the demonstration was successful, even though it wasn't a QTC criterion. 

“There were other ongoing demonstrations near our magnetometers,” he said. “People and robots were walking around near our demonstration and train lines were running directly beneath the convention center. But none of those activities adversely affected the performance of our software augmented sensors.”

That demonstrates the quality of Q-CTRL’s quantum sensors used for QTC. It is not only difficult, but also vitally important for quantum sensors to filter out unrelated background noise and suppress what is unrelated so that results reflect only what the sensor was designed to detect. 

Going forward

According to the Q-CTRL website, its key markets include an $8B annual earth observation market and a $14B annual collective market for positioning, navigation, and timing (PNT). When asked how quantum sensors would be marketed, Dr. Beircuk reaffirmed Q-CTRL’s previously stated strategy. 

“We are not in the business of building and selling widgets,” he said. “We sell software licenses, and we sell IP licenses, and we sell capability, but we don’t sell hardware.”

With Q-CTRL’s successful Army QTC demonstration now behind it, Dr. Biercuk said the research team is looking forward to following up that success with continued development on another sensing project. 

Q-CTRL currently has a partnership with Sydney, Australia based Advanced Navigation, a manufacturer of AI-enhanced inertial navigation systems. Q-CTRL is doing development work on an ultra-high-performance quantum PNT system and plans to license the IP to Advanced Navigation since it is an expert mil-spec manufacturer. Advanced Navigation will also handle the system integration and product distribution. 

“The next stage of our contract with Advanced Navigation calls for Q-CTRL to deploy and validate our platform’s performance under actual field conditions,” Dr. Biercuk said. “We've done a lot of laboratory demonstrations and validations under contract. Next, we’ll put the system on a boat and test its performance under real conditions. It’s very exciting for the team.”

Analyst Notes

Q-CTRL has already demonstrated it can build sophisticated quantum sensors. Up until now, the majority of its technical focus has been on agnostic quantum computing software that addresses errors and the instability of NISQ quantum hardware. Q-CTRL currently has three main products: Boulder Opal, Black Opal, and Fire Opal. It is well documented that Boulder Opal and Fire Opal significantly improve quantum computing by mitigating quantum errors, optimizing quantum hardware, and improving algorithmic and logic operations. Black Opal is a sophisticated but simple and understandable quantum training program. 

Q-CTRL’s proven technical capabilities and its deep expertise with quantum control software points to the sure success of its new quantum sensor division, which will likely serve to significantly advance the science of quantum sensing. I believe the entire quantum ecosystem will eventually benefit from Q-CTRL’s advanced quantum sensing research.

Paul Smith-Goodson is Vice President and Principal Analyst for quantum computing, artificial intelligence and space at Moor Insights and Strategy. You can follow him on Twitter for more current information on quantum, AI, and space.