FAQs
asked about.
General questions about diamond
Why diamond for quantum technologies?
Quantum technologies are on everyone’s lips. The third wave of revolution is in full swing and diamond could play a decisive role due to its atomic properties. The lattice structure ensures that applications in the field of quantum sensor technology or quantum computing can be operated at room temperature, while the large band gap ensures simultaneous optical addressability.
What is a diamond quantum sensor?
Quantum sensors can measure the smallest variables with a very high spatial resolution down to individual nuclear or electron spins. In the case of diamond, these are usually magnetic fields, pressure and temperature.
What is a quantum computer?
A computer that can use the laws of quantum physics to solve certain problems more efficiently than its conventional, classical counterpart. In contrast to classical Bits, it uses so calles Qubits as the smallest building parts of quantum processors.
Advantages of Diamant over other technology platforms?
Compared to other technologies that can be considered for quantum technology applications, diamonds have the decisive advantage that they can be used at room temperature and that they do not break down on geological time scales. Furthermore, not much energy is required to operate diamond-based quantum sensors and computers.
Additionally, its small packaging size allows to envision mobile, very compact quantum computers that might fit into a lunch box. This advantage is unique among existing quantum computing architectures.
Disadvantages of Diamant compared to other technology platforms?
A major disadvantage of diamond compared to other material classes, such as silicon for example, is that it is not very well researched and difficult to treat. IN quantum computing it still lacks in evolution compared to e.g. superconducting qubit systems whereas in bi-medical appliactions the chemical inertness of the diamond surface hinders the efficient attachment of bio-molecules for quantum sensing applications.
What is synthetic diamond?
A synthetic diamond is a diamond that was not created naturally in the earth’s interior, but in an artificial way in a laboratory. This material is much purer than natural diamond, as it can be grown for special purposes (e.g. quantum sensing or quantum computing). For most quantum technology applications, the natural diamond material cannot be used due to the large number of color and defect centers present.
Questions about istopically-enriched diamond
What is isotope-enriched diamond?
The natural occurrence of the carbon isotope is mainly composed of the two classes 12C (98.9%) and 13C (1.1%). This is also found in natural diamonds. In artificially produced (synthetic) diamonds, this ratio can be manipulated to achieve the desired properties for quantum sensor technology (less 13C) or quantum computing (more 13C).
Why do we need isotope-enriched diamonds?
The isotope 13C has a nuclear spin of I=1. In the case of a quantum sensor, this nuclear spin in the diamond leads to interference during the measurement. The absence of this source of interference therefore leads to improved sensitivity. On the other hand, quantum computing relies precisely on these nuclear spins naturally present in the diamond, as they are naturally well shielded against influences from the environment and can therefore be used very well as qubits in quantum computers.
How can isotopically enriched diamond be produced?
Isotope-enriched diamond is produced using artificial diamond production processes. Typically, these are the high-pressure, high-temperature (HPHT) process and the chemical vapor deposition (CVD) process. The isotope ratio is determined during diamond production and cannot be changed afterwards.
Questions about NV-centers
What is the difference between "good" NV centers and "bad" NV centers?
The performance of NV centers as (nanoscale) magnetic field sensors in quantum sensing or qubits in quantum computing is deduced from several electro-optical properties of the NV centers. In the rating of NV centers, the criteria always have to be evaluated always in view of the application. NV centers for nanoscale NMR wide-field magnetic imaging are usually close to the diamond surface and thus suffer from decoherence originating from this (mostly) uncontrollable interface. Here, especially the stability of its negative charge state as well as coherence time are of interest and form indicators for the NV performance and suitability.
In the application field of wuantum computing, the NV centers are usually deeper in the diamond and already possess long (up to milliseconds) coherence times. Here, the coupling strength and efficacy to other spins (NV centers or 13C nuclear spins) within the diamond matrix are the parameter that determine the performance of NV centera as qubit registers.
How can NV centers be created?
NV centers are found in natural diamonds that have been created statistically underground over thousands of years. The conditions prevailing there (high pressure and high temperature) make it possible to create them. In order to create NV centers artificially, either nitrogen doping is used during a CVD diamond growth process, in which NV centers are created directly during growth, or a post-processing method is used. The latter is either vacuum activation by means of electron irradiation or the nitrogen ion implantation process in which nitrogen ions are accelerated and targeted onto an existing diamond. Both post-processing methods are completed by a high-temperature annealing step at around 1000 °C in vacuum.
Why is an NV Center important for applications in the field of quantum technologies?
NV centers are very small. They are the size of a single atom. This means that they can be brought very close to other quantities and objects to be measured. This means that the smallest magnetic fields can be measured with a very high spatial resolution. And the best thing is, these measurements all work at room temperature.
What is an NV center?
An NV center is an atom sized point defect in diamond. The fluorescent color center has extraordinary properties, first and foremost it has an electron spin that can be initialized and read outoptically. Furthermore, its spin state can be coherently controled using microwave signals. These properties enable the operation of quantum sensors and quantum computers based on the NV center in diamond at room temperature.
Questions about the manufacturing process
What can Ion Implantation be used for/for which products?
The implantation method can be used to create nitrogen, silicon or other group-IV based color centers in diamond. These color centers can be positioned with high depth resolution and thus have very homogeneous optical and magnetic properties. The range of products in which they can be used therefore extends from quantum sensors to quantum computing and quantum communication (QKD, quantum key distribution).
What is Ion Implantation?
In nitrogen ion implantation, nitrogen molecules (N2) are ionized (N+) and directed towards a target using an accelerating voltage. In the case of diamond quantum technology, this target is typically a diamond platelet or a diamond layer. With energies of a few keV to MeV, the nitrogen ions hit the diamond, penetrate and finally come to a rest. These nitrogen atoms are now available for the generation of NV centers. These are activated by a final high-temperature annealing step at temperatures of around 1000 °C in vacuum.
What for / For which products can CVD growth be used?
Isotopically pure diamond material can be produced using the CVD (chemical-vapor-deposition) method. This can be performed both nitrogen-free and nitrogen-rich. This means that intrinsic diamonds as well as NV-rich diamonds can be produced. These types of diamond are especially intersting for aplication in the areas of quantum computing or quantum sensing.
What is CVD growth of diamond?
Diamond is naturally formed under high pressure and high temperature in thermodynamic equilibrium. However, it is possible to run a non-equilibrium process and thus grow diamond at lower pressures. This diamond growth is achieved using the chemical vapor deposition (CVD) method.
Here, hydrogen is used as a carrier gas, which prevents the formation of carbon allotropes other than diamond. Methane is usually used as the carbon source for growth and introduced into the growth chamber.
Questions about Diatope
What is Diatope?
Diatope is a spin-off of the University of Ulm and was founded in 2021. The company is managed by the three co-founders, Christoph Findler, Dr. Johannes Lang and Dr. Christian Osterkamp. The dynamic and motivated team is completed by Philipp Vetter, Martin Bräuer, Yarden Hagian, Dr. Simon Schmitt and Allegra de Gleria Clark. You can find our current job advertisements at About us.
Why is Diatope material so reliable and good?
Our value includes unique processes, deep know-how of quantum diamond and a talented team of young engineers and entrepreneurs. Combined with a holistic engineering approach, we gatzher all necessary fabrication techniques to enable a stable and reliable supply of applicaions tailored CVD diamond with NV centers engineered on the nanoscale.
What is unique about Diatope?
We are a team of world leading quantum engineers with an entrepreneural mindset. Additionally, we are supported by two of the most renowned researchers in quantum technology and CVD diamond growth worldwide. We combine unique know-how in CVD diamond and color centers for quantum applications with novel fabrication equipment and characterization techniques with atomic precision to supply NV diamond material perfectly suited for applications in quantum sensing and quantum computing.
Mixed Questions
Why do we need isotope-enriched diamonds?
The isotope 13C has a nuclear spin of I=1. In the case of a quantum sensor, this nuclear spin in the diamond leads to interference during the measurement. The absence of this source of interference therefore leads to improved sensitivity. On the other hand, quantum computing relies precisely on these nuclear spins naturally present in the diamond, as they are naturally well shielded against influences from the environment and can therefore be used very well as qubits in quantum computers.
What is synthetic diamond?
A synthetic diamond is a diamond that was not created naturally in the earth’s interior, but in an artificial way in a laboratory. This material is much purer than natural diamond, as it can be grown for special purposes (e.g. quantum sensing or quantum computing). For most quantum technology applications, the natural diamond material cannot be used due to the large number of color and defect centers present.
What is a diamond quantum sensor?
Quantum sensors can measure the smallest variables with a very high spatial resolution down to individual nuclear or electron spins. In the case of diamond, these are usually magnetic fields, pressure and temperature.
What is an NV center?
An NV center is an atom sized point defect in diamond. The fluorescent color center has extraordinary properties, first and foremost it has an electron spin that can be initialized and read outoptically. Furthermore, its spin state can be coherently controled using microwave signals. These properties enable the operation of quantum sensors and quantum computers based on the NV center in diamond at room temperature.
