If there's an emoji that perfectly encapsulates quantum computing, it's the exploding head.

Consider, for example, that the temperature of most quantum processing chips must be kept as close to absolute zero (roughly -460 degrees Fahrenheit) as possible. Or that some physicists think quantum computing is “the first technology that allows useful tasks to be performed in collaboration between parallel universes.” Or that a quantum computer recently “made history go backward.” True, it was only a simulation, but still — brain blowing stuff.

Before we get carried away, though, let’s consider the foundational basics. Classical computers operate using binary bits, storing data and running processes using ones and zeroes. Quantum machines, however, run on multi-state components called qubits, which can reach the “superposition” of essentially being both one and zero while also “entangling” in combined states. In lay terms, that means quantum computers can do lots of things typical computers can't, including crunching massive amounts of complex information faster than an over-caffeinated cheetah in a time-lapse video.

At this point, imagining those applications is a bit like daydreaming about Christmas in May: there's plenty of anticipation and even wonder, but the big day itself remains a long way off. That's because so far, no one approach to quantum computing has proven ideal. Also, the key work of stabilizing those qubits is arduous and expensive. As theoretical computer scientist Scott Aaronson told Gizmodo, “actually building a useful quantum computer is a massive technological undertaking.”

Even so, an increasing number of companies — including well-funded startups and several major players (think Google, IBM, Microsoft) that have partnered with research institutions to pool wallets and brain power — are trying to close the gap between present and future. When quantum computing is perfected, they know, it will transform a host of industries: medicine, fusion energy, plasma science, climate change, electric vehicles, finance, artificial intelligence and (in rather scary ways) information security.

Which company will lay claim to the first big quantum-computing breakthrough? Check out these 20 leading contenders.

Strangeworks

Location: Austin, Texas

What it does: With apologies to poetic pioneer Peter Shor, the biggest personality in quantum computing is probably William Hurley, aka Whurley, the Austin serial entrepreneur who heads up Strangeworks. The impressively bearded founder is well-known for headline-grabbing stunts, like the time he zapped an intern with a Taser-strapped drone. But he’s a serious quantum evangelist whose company completed a $4 million seed round last year, while eyeing a near-term goal of launching quantum-application subscription services for the aerospace, energy, pharmaceutical and finance industries. Fun fact: He’s also the coauthor of Quantum Computing for Babies.

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Zapata Computing

Location: Cambridge, Mass.

What it does: Quantum Circuits isn’t the only Ivy League quantum spinoff. Using proprietary technology and exclusive algorithms developed at Harvard University, Zapata Computing — not unlike QC Ware — is building quantum software platforms with big-fish enterprise companies in mind. (A recent round of $21 million VC money will help the cause.) According to Forbes, Zapata is making virtual chemistry, machine learning and optimization its first-wave QC focal points.

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ColdQuanta

Location: Boulder, Colo.

What it does: While you can’t exactly hit up TaskRabbit when your quantum computer needs help, service and product support are must-haves for developers. ColdQuanta manufactures various quantum components like vacuum systems and processors to keep atoms brutally cold, which aids the all-important work of cutting down qubit motion and noise. The startup recently brought on D-Wave veteran Bo Ewald as president and CEO.

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Rigetti Computing

Location: Berkeley, Calif.

What it does: When XPRIZE founder Peter Diamandis listed what he believes to be the three “major players” in the push toward quantum supremacy in America, he named two titans (Google and IBM) and one startup: Rigetti Computing. Rigetti recently announced the public beta of its Quantum Cloud Services platform, which the company calls the first cloud service powered by quantum computing.

IonQ

Location: College Park, Md.

What it does: It’s tempting to reduce quantum computing to a simple numbers game, namely number of total qubits. The truth is, you have to consider qubit quality rather than mere quantity. Still, when IonQ last year bested the qubit counts of IBM (50) and Google (72) with its 160-qubit processor, jaws dropped. Whereas most QC companies employ superconductors, IonQ — which recently welcomed famed Amazon Prime boss Peter Chapman as CEO — is pioneering the trapped-ion method through which ions are isolated in a vacuum chamber and subatomic particles are cooled via lasers, eliminating the need for the gigantic copper-looking contraptions that are common to quantum computers.

QC Ware

Location: Palo Alto, Calif.

What it does: A developer of enterprise software for quantum computers, QC Ware counts Citi and Goldman Sachs among its investors. It has also teamed with a number of other outfits, including D-Wave, IBM and, perhaps most notably, Google, whose open-source quantum interface Cirq was recently integrated into QC Ware’s cloud service. 

IBM

Location: Armonk, N.Y.

What it does: Most quantum computing developers are pursuing the universal gate model, rather than, say, annealers (more on those later). The gate model puts qubits into circuits, not unlike traditional ones-and-zeros bits, via superconducting. Tech mainstay IBM is a leader in this lane, having developed at least eight gate-model prototypes, one as high as 50 qubits. (That’s a lot.) Earlier this year, IBM unveiled the Q System One, a step forward for stability and commercial research. It also recently partnered with Exxon Mobil to work on a network that, both parties hope, could lead to innovations in predictive climate models and electric grid management.

D-Wave Systems

Location: Burnaby, B.C.

What it does: About that annealing. In the simplest terms, the quantum annealing process aims to return the lowest possible energy solutions by focusing mostly on questions of optimization. D-Wave Systems — which recently announced their least “noisy” entry, the Pegasus — is most synonymous with this approach. But is it actually quantum? Not really, some critics say. It doesn’t operate on the gate model, which means Pegasus’ ultra-high qubit rate isn’t really all that comparable to almost all of D-Wave’s contemporaries. Still, its hybrid software developments could very well help advance QC's thorny question of scalability.

QxBranch

Location: Washington, D.C.

What it does: Quantum computing is poised to revolutionize fintech, where its supercomputing prowess will simplify risk management, credit scoring, portfolio optimization and just about every other facet of finance. (You won’t be surprised to learn that Goldman Sachs invests in D-Wave Systems.) Data analytics company and IBM partner QxBranch is building quantum computing software — rather than hardware — that could prove a boon in this context. Another predictive bona fide: it’s poised to out-predict Nate Silver, creating gobsmackingly sophisticated election forecasting models.

Quantum Circuits

Location: New Haven, Conn.

What it does: Founded in 2015 by three veterans of Yale’s applied physics department, Quantum Circuits unveiled its testing facility this past January. The cofounders are considered trailblazers in quantum computing with superconducting circuits (hence the name), and the company is illustrative of the science-meeting-tech, academia-meeting-big-business cross-pollination that marks the quest for quantum supremacy.

Bleximo

Location: Berkeley, Calif.

What it does: The exponential boost in data-processing power that quantum computing holds over classical computing opens the door for a, well, quantum leap in pharmaceutical research. Bleximo — which raised $1.5 million in seed funding and was named to the Cyclotron Road fellowship last year — has singled out QC-enabled medical development as its first practical goal. To that end, the company is trying to develop what it calls “quantum accelerator,” essentially quantum-based computational systems designed for a single, specific application, its narrower use being a tradeoff for greater performance.

1QBit

Location: Vancouver, B.C.

What it does: On the topic of pharma research, 1QBit made waves when it partnered with two major players: tech consultants Accenture and biotech multinational Biogen. The ultimate goal is to use quantum computing to create a molecular modeling application, which in turn could lead to breakthroughs in drug development to treat neurodegenerative conditions like dementia. The early-entry quantum company, founded in 2012 and described by Forbes as “the world’s first dedicated quantum computing focused commercial business,” also teamed with Dow Chemical Company in 2017 to explore how nature-simulating QC might propel materials science.

Xanadu

Location: Toronto

What it does: This well-financed Toronto startup is notable for exploring photonic quantum computing, which uses the quantum properties of light particles to run. Last year it released free, open-source software that basically lets anyone run commands on publicly accessible, cloud-based quantum computers, like the IBM Q Experience or the University of Bristol’s Quantum in the Cloud — part of a wider push to familiarize enthusiasts with QC operational basics. More recently, Xanadu announced a whopping $32 million in early stage financing.

Intel

Location: Santa Clara, Calif.

What it does: Venerable processor-maker Intel has been seriously exploring quantum computing since at least 2015, when it partnered with leading Dutch research group QuTech. Among its most recent contributions to the cause: a first-of-kind QC testing device, dubbed a cryoprober. The tool purportedly can (relatively) quickly measure qubit characteristics even at the hundreds-below-zero temperatures often required for qubit stabilization, speeding up a process that once took days just to gather small amounts of data. As for the long term, according to its director of quantum hardware, Intel is eyeing nothing less than a million-qubit system — the number at which truly transformational power will occur.

ISARA Corporation

Location: Waterloo, Ont.

What it does: RSA security encryption relies on prime numbers to secure your information. More specifically, it relies on the fact that prime factorization of large numbers is prohibitively time-consuming for would-be hackers. But if a quantum computer powerful enough to run Shor’s factorization algorithm ever came along, all that security essentially vanishes. This looming threat has birthed an entire sub-industry dedicated to patching potentially huge vulnerabilities. Isara has emerged as an early frontrunner, working to develop security systems that essentially allow communication between classical and quantum algorithms.

Google

Location: Mountain View, Calif.

What it does: The as-yet still-theoretical concept of “quantum supremacy” is easily explained (the power of quantum computers to perform tasks that classical computers can't) and extremely difficult to achieve. Some developers claim its arrival is imminent; others say it’s several years away. Google’s Research wing, which has partnered with NASA to win the great quantum supremacy races, appears to be in the former camp. Hartmut Neven, director of the tech giant’s Quantum Artificial Intelligence lab, recently told Quanta that quantum computers are growing “doubly exponential” where “it looks like nothing is happening, nothing is happening, and then whoops, suddenly you’re in a different world.”

Microsoft

Location: Redmond, Wash.

What it does: While most quantum-computing research hitches its qubits to the superconductor/solid-state wagon or, to a lesser degree, trapped ions, Microsoft rolls along a third route: topological qubits. These qubits would sidestep so many pesky stability requisites (those mind-bogglingly cold temps, no physical vibrations) by splitting an electron — essentially, double anti-interference protection — and exhibiting two ground states (a.k.a. ground state degeneracy). We say “would,” however, because the process still remains strictly theoretical.

Honeywell

Location: Charlotte, N.C.

What it does: Despite years of gestation, this many-tentacled conglomerate only recently peeled back the lab curtains on its quantum efforts. Somewhat surprisingly, Honeywell is going the less-traveled trapped-ion route, similar to IonQ. Honeywell runs its trap system with ytterbium atoms, which it claims has a leg up over solid-state competitors. “Because each of these atoms is identical, defined in nature by its atomic structure, our system can be uniformly formed and controlled more easily and quickly compared to alternative systems that do not directly use atoms,” says president Tony Uttley, a former operations manager at NASA. It was apparently enough to convince the Canadian Space Agency, which recently inked a multi-million deal with Honeywell to run a satellite mission to test quantum encryption.

Atom Computing

Location: Berkely, Calif.

What it does: As its names hints, Atom Computing uses qubits made from neutral atoms, described by Science as a “dark horse candidate” in the quantum-computing sweepstakes. Backed by at least $5 million in venture capital and founded by Benjamin Bloom, a former senior quantum engineer at Rigetti and member of the team that “smashed” the atomic clock record, Atom hopes its novel approach will lead to scalable beyond-super computers that advance pharmaceutical research, computational chemistry and more.

ProteinQure

Location: Toronto

What it does: North of the border, the Creative Destruction Lab non-profit has incubated several notable quantum alumni, including Xanadu, D-Wave partners Solid State AI and this forward-thinking biotech startup. A Rigetti partner, ProteinQure uses quantum computing and machine learning to computer-simulate designs for protein-based drugs.

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