A Bit About Connecting Qubits: Quantum Computing

A Bit on Bits

“In or out!” my mom would scream at me when I was growing up. “Make up your mind and decide if you are going outside or coming inside. You are wasting energy standing in the doorway,” she’d bellow.

I am not sure whether my mom knew much about the coming digital age, a world that was to be transformed by the power of the binary digit (bit). But maybe she knew more about technology than she led on in my childhood years.

I wonder whether my mom knew that bits are characterized as a two-stage (0, 1) mathematical representation analogous to opposite binary states such as ON/OFF, HIGH/LOW, IN/OUT. Bits allowed classical computers to take center stage in the digital revolution.

Transcending Bits: Hello Qubits

But a new revolution is underway — a computational breakthrough well beyond the current boundaries imposed by a binary system. This computing revolution is quantum computing, which replaces bits with quantum bits (qubits) (Figure 1). Qubits, through a phenomenon known as quantum superposition, can be in two states at the same time — which reminds me of my mother’s directive of being either in or out.

Quantum superposition allows quantum computers to process vast amounts of data simultaneously in a single operation — a task that could take a classical computer thousands of years to accomplish.

Figure 1: The image illustrates how a qubit occupies two states at one time. (Source: ©stock.adobe.com/au/Astibuag)

Qubit manipulation is the mechanism that carries out quantum computing operations. RF connectors, adapters, and cable assemblies are used in quantum computing to transmit signals that manipulate the state of qubits. Specific interconnect features required include the ability to withstand cryogenic (very low) temperatures, non-magnetic, high-frequency, and low loss.

Amphenol RF

Amphenol RF leads the way in addressing this new market. Amphenol RF, a division of Amphenol Corporation, is the world’s largest manufacturer of coaxial interconnect products for radio frequency (RF), microwave, and data-transmission applications. As a leader in enabling next-generation technology, Amphenol RF continually supports global advancements in connectivity. Whether it is high-frequency coaxial connectors and wiring harnesses for high-isolation delivery of electromagnetic control signals, microwave connectivity solutions, or connectors, Amphenol RF is connecting the way for quantum revolution. Let’s look at some of the Amphenol RF products making quantum computing come to realization.

Conformable Cable Assemblies

What does one use to provide a flexible connection option to route high-frequency signals within quantum computing applications? One might consider Subminiature version A (SMA) High-Frequency Semi-Rigid Cable Assemblies, such as the 135101-R1-12.00 (Figure 2). It is an RF Cable Assemblies SMA (50Ω) Straight Plug to Straight Plug, Ǿ 2.16mm (0.085″). It is available in other lengths ranging from 76mm–1219mm (3″–4′).

Figure 2: The Amphenol RF SMA High-Frequency Semi-Rigid Cable Assembly offers a flexible connection option for routing high-frequency signals within quantum computing applications. (Source: Mouser Electronics)

SMAs come with a threaded coupling mechanism. They are designed to be small in size and have low RF leakage. They can operate across frequencies of up to 26.5GHz. If higher frequencies are involved, look to the 2.92mm (0.114″) series from Amphenol, which offers an extended frequency range of up to 40GHz. SMAs terminate to a wide range of high-performance cables. Amphenol RF SMAs include PCB-mount and cable-mount connectors, as well as a variety of adapters, terminators, attenuators, and cable assemblies to meet a variety of designs. Conformable Cable Assembly options include:

• SMA to SMA
• SMP to SMP
• SMPM to SMPM
• SMA to SMP
• TFLEX cable options

SMA End Launch Connectors

SMA High-Frequency End Launch Jacks help consistently maintain the signal from a Qubit PCB. An example would be Amphenol RF’s 901-10513-1 (Figure 3). Precision-machined using a beryllium copper (BeCu) with gold plating contact, these products offer excellent Voltage Standing Wave Ratio (VSWR) performance up to 26.5GHz and are available for multiple, different PCB thicknesses. The connectors feature an optimized end launch design with either through-hole legs or traditional slide-on mounting legs that make them an ideal PCB connector solution for high-frequency applications.

Figure 3: The SMA High-Frequency End Launch Jacks from Amphenol RF reliably maintain the signal from a Qubit PCB. (Source: Mouser Electronics)

Space-Constrained Solutions

The subminiature push-on (SMP) high-frequency PCB connector interface is significantly smaller than an SMA connector for deployment in space-constrained applications (Figure 4). It is useful for board-to-board designs in quantum computing. The SMP connector offers an extended frequency range of up to 40GHz for highly optimized products. Its three-piece, board-to-board connector design is blind mateable. It may be terminated to semi-rigid conformable or flexible semi-rigid alternatives. Amphenol RF provides it in various PCB mounting options. It features limited detent and full detent options to secure a mating connector or bullet adapter. Examples from Amphenol RF include the SMP-MSLD-PCT19T and SMP-MSSB-PCS17T.

Figure 4: SMP High-Frequency PCB Connectors from Amphenol RF are well-suited for compact board-to-board designs in quantum computing applications. (Source: Mouser Electronics)

Similar to the SMP series, but yet even smaller, is the SMPM Micro-Miniature High-Frequency PCB connector for board-to-board quantum computing designs (Figure 5). For applications up to 65GHz, SMPM connectors feature a snap-on mating style similar to SMP connectors and are ideal for a range of precision and miniaturized applications. Amphenol RF machines SMPM PCB connectors from brass with gold plating for solderability and high-frequency electrical performance. Surface mount, through-hole leg, or edge-mount terminations are available. Users can pair these connectors with SMPM bullet adapters, achieving a minimum PCB spacing of 8.65mm. These PCB connectors paired with bullet adapters are ideal for blindmate situations. SMPM cable connectors are made from beryllium copper or brass with gold plating for durability of use and maximum electrical performance. Examples include the 925-196J-51PT and 925-197J-51PT.

Figure 5: SMPM High-Frequency PCB Connectors from Amphenol RF provide a Micro-Miniature connector option for board-to-board designs in quantum computing applications. (Source: Mouser Electronics)

Conclusion

The future of quantum computing applications relies on secure high-frequency electrical connections. Amphenol RF is the supplier that is bringing the necessary connection technologies to reality.

I look forward to the day when I am handed a new qubit computing platform from my employer to write on. Hopefully, its computational superpowers from the qubit will spill over into my writing, and I will move from producing hundreds of words of writing per day to … well, we shall one day see. But until then, I must stand on the sideline, answering the question many of us have: Am I in or out?

*Paul Golata joined Mouser Electronics in 2011. As a Senior Technology Specialist, Paul contributes to Mouser’s success through driving strategic leadership, tactical execution, and the overall product-line and marketing directions for advanced technology related products. He provides design engineers with the latest information and trends in electrical engineering by delivering unique and valuable technical content that facilitates and enhances Mouser Electronics as the preferred distributor of choice.

Before joining Mouser Electronics, Paul served in various manufacturing, marketing, and sales related roles for Hughes Aircraft Company, Melles Griot, Piper Jaffray, Balzers Optics, JDSU, and Arrow Electronics. He holds a BSEET from the DeVry Institute of Technology (Chicago, IL); an MBA from Pepperdine University (Malibu, CA); an MDiv w/BL from Southwestern Baptist Theological Seminary (Fort Worth, TX); and a PhD from Southwestern Baptist Theological Seminary (Fort Worth, TX).

Top image credit: ©stock.adobe.com/au/zapp2photo

Originally published here.