ColdQuanta Could Become the Fastest Scaling Quantum Computer Approach

Nextbigfuture interviewed Tom Noel, ColdQuanta’s Director of Quantum Computing and Interim CEO Dan Caruso. ColdQuanta is using neutral atoms instead of trapped ions as the basis for its quantum computers.

ColdQuanta is building a functional first system now and believes they will be able to scale to the 1000s of qubits faster than competing approaches. If usable quantum systems are created with high entanglement times and thousands of qubits then there will be massive advances with optimization problems, machine learning, materials research and chemistry simulation applications. Cracking major optimization problems could improve the efficiency of large-scale logistics at the scale of Fedex and the US military. Advances with chemistry will be beneficial for many industries including drugs and agriculture. The economic impacts would scale into the trillions.

There are three major reasons the neutral atom approach should become dominant:
1. Ion qubits used in ion-trapping are positively charged. Both Honeywell and IonQ use what are called Paul traps, which use a radiofrequency electric field for trapping. Honeywell’s architecture uses physical motion to bring qubits into position to perform operations. IonQ’s architecture has fixed positions. The main point #1 about scaling that I was trying to make is that using neutral cold atoms as qubits simplifies using dense 2D arrays of qubits, compared to existing commercial ion trap architectures, which are limited to 1D chains. The dimensionality of the array makes faster scaling of qubit count possible.

The neutral atoms in an optical laser trap array can remain stationary. Electrons get activated to expand the range of quantum interactions. Neutral atoms will be trapped using a laser field and will be separated by about 2 to 10 microns of when held in the array.

Neutral atoms that do not have to be moved for quantum calculations will greatly simplify operations compared to ion-based approaches.

2. High Connections

DWave Systems, adiabitic quantum computing, has a high number of inferior superconducting qubits. DWave has created many versions of their chips and goes to great effort to increase the connections between different 16 qubit cells. The Google superconducting gate quantum computer has a connection level of about 4. Each qubit is connected to four others. The IBM superconducting gate computer has two to three connections per qubit. ColdQuanta will start with four connections and then scale up from there.

3. Entanglement

Trapped ion and neutral atoms approaches have far higher entanglement times. The superconducting approaches have severely limited entanglement times.

Lengthening entanglement times increases the numbers of operations and computing power for the systems. The entanglement metric helps to improve the depth of calculations possible with a quantum system. The number of qubits is the breadth while entanglement and speed of operations are major factors in the depth.

Currently, simulation of quantum systems with classical computing can have breadth but are severely limited on depth. True quantum systems that outperform on depth will be able to do what classical computers cannot.

Some near-term accessible “variational quantum algorithms” appear to need only circuit depth on the order of the logarithm of the qubit count to be successful. Thus the quantum volume metric, which demands equal depth and qubit count does not represent the capabilities of near-term machines on a likely class of near-term algorithms.


There are major markets for using quantum computers for optimization problems, machine learning, materials research and chemistry simulation.

ColdQuanta is working with Argonne National Labs and other partners on QAOA and VQE. Quantum Approximate Optimization Algorithms and Variational-Quantum-Eigensolver algorithms are the basis for progress in the application areas.

Background on Rydberg-Rydberg Interactions and Neutral Atoms for Quantum Computers

There are various research papers discussing the usage of Rydberg-Rydberg interactions for quantum gates.

One electron on each atoms is excited into a Rydberg state.

Nature Physics – A boost to Rydberg quantum computing

Systems of neutral atoms are gradually gaining currency as a promising candidate for realizing large-scale quantum computing. The achievement of a record-high fidelity in quantum operation with alkaline-earth Rydberg atoms is a case in point.

Nature Physics – High-fidelity entanglement and detection of alkaline-earth Rydberg atoms

Trapped neutral atoms have become a prominent platform for quantum science, where entanglement fidelity records have been set using highly excited Rydberg states. However, controlled two-qubit entanglement generation has so far been limited to alkali species, leaving the exploitation of more complex electronic structures as an open frontier that could lead to improved fidelities and fundamentally different applications such as quantum-enhanced optical clocks. Here, we demonstrate a novel approach utilizing the two-valence electron structure of individual alkaline-earth Rydberg atoms. We find fidelities for Rydberg state detection, single-atom Rabi operations and two-atom entanglement that surpass previously published values. Our results pave the way for novel applications, including programmable quantum metrology and hybrid atom–ion systems, and set the stage for alkaline-earth based quantum computing architectures.

Arxiv – Quantum Computing with Neutral Atoms
The manipulation of neutral atoms by light is at the heart of countless scientific discoveries in the field of quantum physics in the last three decades. The level of control that has been achieved at the single-particle level within arrays of optical traps, while preserving the fundamental properties of quantum matter (coherence, entanglement, superposition), makes these technologies prime candidates to implement disruptive computation paradigms. In this paper, we review the main characteristics of these devices from atoms / qubits to application interfaces, and propose a classification of a wide variety of tasks that can already be addressed in a computationally efficient manner in the Noisy Intermediate Scale Quantum era we are in. We illustrate how applications ranging from optimization challenges to simulation of quantum systems can be explored either at the digital level (programming gate-based circuits) or at the analog level (programming Hamiltonian sequences). We give evidence of the intrinsic scalability of neutral atom quantum processors in the 100-1,000 qubits range and introduce prospects for universal fault-tolerant quantum computing and applications beyond quantum computing.

A brief overview of the prospects in terms of hardware development.

1. The number of qubits available for computation is mostly limited by the current trapping laser system. On the one hand, the development of new laser systems delivering much higher optical power would enable the generation of many more optical tweezers. Together with an improved imaging system based on state-of-the-art microscope objectives, this would allow to scale the size of the register up to a few thousands of qubits. At this point, the lifetime of the atoms forming a sub-register configuration also becomes a limitation. Because the latter is set by the residual pressure in the vacuum chamber, it motivates another major future development: the design of QPUs in compact cryogenic environments.

2. The other way to overcome the limitation set by the residual pressure is to reduce the duration of each operation occurring in a computation cycle with respect to the atoms lifetime. First, the development of high-flux atomic sources would allow to reduce the time required to load the registers. Then, a set of new hardware and techniques would be combined to reduce the time required to assemble a defect-free sub-register of atoms, and the time to acquire images. Overall, the repetition rate is expected to improve by an order of magnitude. Even though the current acquisition capabilities enable the realization of most experiments, the overall increase of the repetition rate will facilitate the implementation of procedures that require a very large number of repetitions, such as variational algorithms.

3. important efforts need to be focused on improving the manipulation of the qubits and reducing the error rate of the quantum operations. In the next generation of neutral atom processors, the electrostatic environment of the atoms will have to be designed with special care to reduce even further the decoherence induced by parasitic

ColdQuanta Announces Dan Caruso as Executive Chairman and Interim CEO
Caruso Sees 2021 as the Dawn of the Quantum Revolution

BOULDER, CO – MARCH 15, 2021 – ColdQuanta, the leader in Cold Atom Quantum Technology, today announced Dan Caruso as its Executive Chairman and interim CEO. Over the past several years, ColdQuanta has developed world leading expertise in the most scalable, versatile, and commercially viable area of quantum – the Cold Atom Method. As Executive Chairman, Dan will oversee the strategic direction and rapid growth of one of the world’s most influential companies in the burgeoning field of quantum computing, sensing and networking.

Dan has deep experience scaling businesses from startup to IPO, and is an active investor in the tech industry. He has been a member of three startups, all of which are valued at over $10 billion: Zayo Group, Level 3 Communications, and MFS Communications. Prior to ColdQuanta, Caruso was the co-founder, chairman and CEO of Zayo Group, a global provider of internet infrastructure. Caruso led Zayo through an IPO to create a multi-billion dollar company. He later took Zayo private and sold the company in March of 2020 in a $14.3 billion deal. Prior to Zayo, Caruso was one of the founding executives of Level 3 Communications and the former CEO of ICG Communications.

“ColdQuanta has 90 fantastic employees, most of whom are quantum physicists, scientists, and engineers. I am excited to support Dr. Anderson, Dr. Mark Saffman, and our other amazing ColdQuanta colleagues,” said Dan Caruso. “ColdQuanta will contribute to a fundamental transformation from humankind’s classical history to its quantum destiny. The company’s innovation in Cold Atom Quantum Technology will play a pivotal role in the most seismic revolution since the launch of the Internet.”

“Dan is a consummate company builder with an impeccable track record of great success and value creation for employees and shareholders,” said Dr. Dana Anderson, CTO and Co-Founder of ColdQuanta. “Under his leadership and vision ColdQuanta will experience massive growth in the application of quantum.”

The story of ColdQuanta begins in 1924 with the discovery of the Bose Einstein Condensate (BEC) – also known as the 5th form of matter – by Albert Einstein and Satyendra Nath Bose. In 1995, Dr. Eric Cornell and Dr. Carl Wieman synthesized the first ever BEC, which occurred at the University of Colorado at Boulder in partnership with the National Institute of Standards and Technology. Cornell and Wieman were awarded the Nobel Prize for their BEC breakthrough. Today, this innovation serves as the foundation of ColdQuanta’s Cold Atom Quantum Method which spans Quantum Computers, Sensing and Networking applications.

Quantum Computing is widely acknowledged to become a multi $100 billion dollar market. Less appreciated is the market opportunity for Quantum Sensing and Networking– which together may surpass Quantum Computing. ColdQuanta’s Cold Atom Method is applicable to all of these markets, reimagining mainstay applications such as Global Positioning Systems to modern Quantum Positioning Systems and the conventional Internet to the Quantum Internet. These beachhead applications pave the way for countless more use cases where extraordinary precision and accurate sensing are required. Harnessing the entanglement property of qubits–the fundamental building block of quantum applications–enables these applications and no company is better positioned to do so than ColdQuanta. “As I dove deeper into ColdQuanta, I began to more fully appreciate the magnitude of the opportunity. I believe ColdQuanta will be my fourth decacorn, and it will by far be the most important,” said Caruso.

Bo Ewald, ColdQuanta’s CEO and a pioneer in supercomputing, has announced his retirement. ColdQuanta’s Board of Directors has embarked upon a search for the company’s next CEO, who will lead ColdQuanta’s transformation into a world leader of quantum computing, networking and sensing applications. Dan Caruso will serve as interim CEO during the search. ColdQuanta’s directors and the team thank Mr. Ewald for his leadership over the past two years. Dr. Tim Day, the company’s existing Executive Chairman, will transition to the ColdQuanta Board.

“It’s been an honor to work with the entire ColdQuanta team while strengthening the foundation of the company,” said Bo Ewald. “I wish the best to my friends in the company, our customers and our partners.”

About ColdQuanta

ColdQuanta is the leader in Cold Atom Quantum Technology, the most scalable, versatile, and commercially viable area of quantum. Coldquanta is dedicated to making quantum matter through the commercial availability of Quantum Computing, Sensing, and Networking Applications. Backed by years of research and development, the story of ColdQuanta began in 1924 with the discovery of the Bose Einstein Condensate (BEC) – also known as the 5th form of matter – and 70 years later brought to fruition when it was first synthesized at the University of Colorado at Boulder in collaboration with the National Institute of Standards and Technology (NIST). ColdQuanta was spawned by this BEC breakthrough. Today, ColdQuanta is collaborating with its global customers, which include major commercial and defense companies; the U.S. Department of Defense; national labs operated by the Department of Energy, NASA, and NIST; major universities; and quantum-focused tech companies, to advance the Cold Atom Quantum Method. ColdQuanta is based in Boulder, CO with offices in Madison, Wisconsin and Oxford, UK. Find out more at

SOURCES- ColdQuanta, Interviews with Tom Noel and Dan Caruso, Arxiv, Nature Physics
Written by Brian Wang,

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